Greatest element of a list
You are encouraged to solve this task according to the task description, using any language you may know.
- Task
Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
11l
11l already has a "Maximum Value" function. <lang 11l>max(values)</lang>
8th
<lang forth> [ 1.0, 2.3, 1.1, 5.0, 3, 2.8, 2.01, 3.14159 ] ' n:max 0 a:reduce . cr </lang> Output: 5
AArch64 Assembly
<lang AArch64 Assembly> /* ARM assembly AARCH64 Raspberry PI 3B */ /* program rechMax64.s */
/*******************************************/ /* Constantes file */ /*******************************************/ /* for this file see task include a file in language AArch64 assembly*/ .include "../includeConstantesARM64.inc"
/*********************************/ /* Initialized data */ /*********************************/ .data szMessResult: .ascii "Max number is = @ rank = @ address (hexa) = @ \n" // message result
tTableNumbers: .quad 50
.quad 12
.quad -1000
.quad 40
.quad 255
.quad 60
.quad 254
.equ NBRANKTABLE, (. - tTableNumbers) / 8 // number table posts
/*********************************/ /* UnInitialized data */ /*********************************/ .bss sZoneConv: .skip 24 /*********************************/ /* code section */ /*********************************/ .text .global main main: // entry of program
ldr x1,qAdrtTableNumbers mov x2,0 ldr x4,[x1,x2,lsl #3] // load first number mov x3,x2 // save first indice add x2,x2,1 // increment indice
1:
cmp x2,#NBRANKTABLE // indice ? maxi bge 2f // yes -> end search ldr x0,[x1,x2,lsl #3] // load other number cmp x0,x4 // > old number max csel x4,x0,x4,gt // if > x4 = x0 else x4=x4 csel x3,x2,x3,gt // if > x3 = x2 else x3=x3 add x2,x2,1 // increment indice b 1b // and loop
2:
mov x0,x4 ldr x1,qAdrsZoneConv bl conversion10S // decimal conversion ldr x0,qAdrszMessResult ldr x1,qAdrsZoneConv bl strInsertAtCharInc // insert result at first @ character mov x5,x0 // save address message mov x0,x3 ldr x1,qAdrsZoneConv // conversion rank maxi bl conversion10S // decimal conversion mov x0,x5 // message address ldr x1,qAdrsZoneConv bl strInsertAtCharInc // insert result at Second @ character mov x5,x0 // save message address ldr x0,qAdrtTableNumbers lsl x3,x3,3 add x0,x0,x3 ldr x1,qAdrsZoneConv // conversion address maxi bl conversion16 // hexa conversion mov x0,x5 ldr x1,qAdrsZoneConv bl strInsertAtCharInc // insert result at third @ character bl affichageMess // display message final
100: // standard end of the program
mov x0,0 // return code mov x8,EXIT // request to exit program svc 0 // perform the system call
qAdrtTableNumbers: .quad tTableNumbers qAdrszMessResult: .quad szMessResult qAdrsZoneConv: .quad sZoneConv
/******************************************************************/ /* conversion hexadecimal register */ /******************************************************************/ /* x0 contains value and x1 address zone receptrice */ conversion16:
stp x0,lr,[sp,-48]! // save registres stp x1,x2,[sp,32] // save registres stp x3,x4,[sp,16] // save registres mov x2,#60 // start bit position mov x4,#0xF000000000000000 // mask mov x3,x0 // save entry value
1: // start loop
and x0,x3,x4 // value register and mask lsr x0,x0,x2 // right shift cmp x0,#10 // >= 10 ? bge 2f // yes add x0,x0,#48 // no is digit b 3f
2:
add x0,x0,#55 // else is a letter A-F
3:
strb w0,[x1],#1 // load result and + 1 in address lsr x4,x4,#4 // shift mask 4 bits left subs x2,x2,#4 // decrement counter 4 bits <= zero ? bge 1b // no -> loop
100: // fin standard de la fonction
ldp x3,x4,[sp,16] // restaur des 2 registres ldp x1,x2,[sp,32] // restaur des 2 registres ldp x0,lr,[sp],48 // restaur des 2 registres ret
/********************************************************/ /* File Include fonctions */ /********************************************************/ /* for this file see task include a file in language AArch64 assembly */ .include "../includeARM64.inc" </lang>
- Output:
Max number is = +255 rank = +4 address (hexa) = 000000000041051C
ACL2
<lang Lisp>(defun maximum (xs)
(if (endp (rest xs))
(first xs)
(max (first xs)
(maximum (rest xs)))))</lang>
Action!
<lang Action!>BYTE FUNC Max(BYTE ARRAY tab BYTE size)
BYTE i,res
res=tab(0)
FOR i=1 TO size-1
DO
IF res<tab(i) THEN
res=tab(i)
FI
OD
RETURN (res)
PROC Main()
BYTE i,m,size=[20] BYTE ARRAY tab(size) FOR i=0 TO size-1 DO tab(i)=Rand(0) OD
Print("Array:")
FOR i=0 TO size-1
DO
PrintF(" %I",tab(i))
OD
PutE()
m=Max(tab,size)
PrintF("Greatest: %I%E",m)
RETURN</lang>
- Output:
Screenshot from Atari 8-bit computer
Array: 106 182 121 251 21 244 46 157 228 251 173 50 106 126 193 230 88 117 114 120 Greatest: 251
ActionScript
<lang ActionScript>function max(... args):Number { var curMax:Number = -Infinity; for(var i:uint = 0; i < args.length; i++) curMax = Math.max(curMax, args[i]); return curMax; }</lang>
Ada
The keys for this task are initializing the compared value to the 'First value of the element type, and use of an unconstrained array type. <lang ada>with Ada.Text_Io;
procedure Max_Test isco
-- substitute any array type with a scalar element
type Flt_Array is array (Natural range <>) of Float;
-- Create an exception for the case of an empty array
Empty_Array : Exception;
function Max(Item : Flt_Array) return Float is
Max_Element : Float := Float'First;
begin
if Item'Length = 0 then
raise Empty_Array;
end if;
for I in Item'range loop
if Item(I) > Max_Element then
Max_Element := Item(I);
end if;
end loop;
return Max_Element;
end Max;
Buf : Flt_Array := (-275.0, -111.19, 0.0, -1234568.0, 3.14159, -3.14159);
begin
Ada.Text_IO.Put_Line(Float'Image(Max(Buf)));
end Max_Test;</lang> A generic function Max to deal with any floating-point type. <lang ada>generic
type Item is digits <>; type Items_Array is array (Positive range <>) of Item;
function Generic_Max (List : Items_Array) return Item;</lang> Implementation of: <lang ada>function Generic_Max (List : Items_Array) return Item is
Result : Item := List (List'First);
begin
for Index in List'First + 1..List'Last loop
Result := Item'Max (Result, List (Index));
end loop;
return Result;
end Generic_Max;</lang> When the argument array is empty, Constraint_Error exception is propagated, because array indexing is checked in Ada. Note also use of the floating-type attribute Max.
Aime
<lang aime>integer lmax(list l) {
integer max, x;
max = l[0];
for (, x in l) {
if (max < x) {
max = x;
}
}
max;
}</lang> or <lang aime>integer lmax(list l) {
integer max;
max = l[0]; l.ucall(max_i, 1, max);
max;
}</lang>
ALGOL 68
<lang algol68># substitute any array type with a scalar element # MODE FLT = REAL;
- create an exception for the case of an empty array #
PROC raise empty array = VOID:(
GO TO except empty array
);
PROC max = ([]FLT item)FLT: BEGIN
IF LWB item > UPB item THEN
raise empty array; SKIP
ELSE
FLT max element := item[LWB item];
FOR i FROM LWB item + 1 TO UPB item DO
IF item[i] > max element THEN
max element := item[i]
FI
OD;
max element
FI
END # max #;
test:(
[]FLT buf = (-275.0, -111.19, 0.0, -1234568.0, pi, -pi); print((max(buf),new line)) EXIT except empty array: SKIP
)</lang>
- Output:
+3.14159265358979e +0
ALGOL W
<lang algolw>begin
% simple list type % record IntList( integer val; reference(IntList) next );
% find the maximum element of an IntList, returns 0 for an empty list %
integer procedure maxElement( reference(IntList) value list ) ;
begin
integer maxValue;
reference(IntList) listPos;
maxValue := 0;
listPos := list;
if listPos not = null then begin
% non-empty list %
maxValue := val(listPos);
listPos := next(listPos);
while listPos not = null do begin
if val(listPos) > maxValue then maxValue := val(listPos);
listPos := next(listPos)
end while_listPos_ne_null ;
end if_listPos_ne_null ;
maxValue
end maxElement ;
% test the maxElement procedure % write( maxElement( IntList( -767, IntList( 2397, IntList( 204, null ) ) ) ) )
end.</lang>
- Output:
2397
Amazing Hopper
Version 1: <lang Amazing Hopper>
- include <hopper.h>
main:
lst=0 max=0 file="datos.txt"
{","} toksep
{file} statsfile
{file} load
mov (lst)
{0} reshape (lst)
{lst} array (SORT)
[end] get (lst)
mov (max)
{"Maximo = "}
{max}
{"\n"} print
exit(0) </lang> Version 2: <lang Amazing Hopper>
- include <hopper.h>
- define SIZE_LIST 100000
main:
lst=-1
max=0
{SIZE_LIST} rand array (lst)
mul by (SIZE_LIST)
mov (lst)
{lst} array (SORT)
[end] get (lst)
mov (max)
{"Maximo = "}
{max}
{"\n"} print
exit(0) </lang>
- Output:
Maximo = 99999.8
AntLang
<lang AntLang>max|range[10]</lang>
APL
<lang apl>LIST←2 4 6 3 8 ⌈/LIST</lang>
- Output:
8
AppleScript
<lang AppleScript> max({1, 2, 3, 4, 20, 6, 11, 3, 9, 7})
on max(aList) set _curMax to first item of aList repeat with i in (rest of aList) if i > _curMax then set _curMax to contents of i end repeat return _curMax end max </lang>
To find the greatest elements of lists which may contain data types other than numbers, we can write a more generic maximumBy function, which returns the maximum value from an array containing a series of any consistent data type, and which takes a type-specific comparison function as an argument.
<lang AppleScript> -- maximumByMay :: (a -> a -> Ordering) -> [a] -> Maybe a on maximumByMay(f, xs)
set cmp to mReturn(f)
script max
on |λ|(a, b)
if cmp's |λ|(a, b) < 0 then
b
else
a
end if
end |λ|
end script
foldl1May(max, xs)
end maximumByMay
-- TEST ----------------------------------------------------------------------- on run
set lstWords to ["alpha", "beta", "gamma", "delta", "epsilon", ¬
"zeta", "eta", "theta", "iota", "kappa", "|λ|", "mu"]
set lstCities to [{name:"Shanghai", population:24.15}, ¬
{name:"Karachi", population:23.5}, ¬
{name:"Beijing", population:21.5}, ¬
{name:"Tianjin", population:14.7}, ¬
{name:"Istanbul", population:14.4}, ¬
{name:"Lagos", population:13.4}, ¬
{name:"Tokyo", population:13.3}]
script population
on |λ|(x)
population of x
end |λ|
end script
return catMaybes({¬
maximumByMay(comparing(|length|), lstWords), ¬
maximumByMay(comparing(|length|), {}), ¬
maximumByMay(comparing(population), lstCities)})
--> {"epsilon", {name:"Shanghai", population:24.15}}
end run
-- GENERIC FUNCTIONS ----------------------------------------------------------
-- catMaybes :: [Maybe a] -> [a] on catMaybes(mbs)
script emptyOrListed
on |λ|(m)
if nothing of m then
{}
else
{just of m}
end if
end |λ|
end script
concatMap(emptyOrListed, mbs)
end catMaybes
-- comparing :: (a -> b) -> (a -> a -> Ordering) on comparing(f)
set mf to mReturn(f)
script
on |λ|(a, b)
set x to mf's |λ|(a)
set y to mf's |λ|(b)
if x < y then
-1
else
if x > y then
1
else
0
end if
end if
end |λ|
end script
end comparing
-- concatMap :: (a -> [b]) -> [a] -> [b] on concatMap(f, xs)
set acc to {}
tell mReturn(f)
repeat with x in xs
set acc to acc & |λ|(contents of x)
end repeat
end tell
return acc
end concatMap
-- foldl1May :: (a -> a -> a) -> [a] -> Maybe a on foldl1May(f, xs)
set lng to length of xs
if lng > 0 then
if lng > 1 then
tell mReturn(f)
set v to item 1 of xs
set lng to length of xs
repeat with i from 2 to lng
set v to |λ|(v, item i of xs, i, xs)
end repeat
return just(v)
end tell
else
just(item 1 of xs)
end if
else
nothing("Empty list")
end if
end foldl1May
-- just :: a -> Just a on just(x)
{nothing:false, just:x}
end just
-- length :: [a] -> Int on |length|(xs)
length of xs
end |length|
-- max :: Ord a => a -> a -> a on max(x, y)
if x > y then
x
else
y
end if
end max
-- nothing :: () -> Nothing on nothing(msg)
{nothing:true, msg:msg}
end nothing
-- Lift 2nd class handler function into 1st class script wrapper -- mReturn :: Handler -> Script on mReturn(f)
if class of f is script then
f
else
script
property |λ| : f
end script
end if
end mReturn</lang>
- Output:
<lang AppleScript>{"epsilon", {name:"Shanghai", population:24.15}}</lang>
Applesoft BASIC
<lang ApplesoftBASIC> 100 REMMAX
110 R$ = "":E$ = "" 120 L = LEN (L$) 130 IF L = 0 THEN RETURN 140 FOR I = 1 TO L 150 C$ = MID$ (L$,I,1) 160 SP = C$ = " " 170 IF SP THEN GOSUB 200 180 E$ = E$ + C$ 190 NEXT I 200 C$ = "" 210 IF E$ = "" THEN RETURN 220 V = VAL (E$):V$ = R$ 230 E$ = "":E = V$ = "" 240 IF E AND V = 0 THEN RETURN 250 R$ = STR$ (V) 260 IF E THEN RETURN 270 R = VAL (V$) 280 IF R < V THEN RETURN 290 R$ = V$: RETURN</lang>
<lang ApplesoftBASIC>L$ = "1 2 3 4 20 6 11 3 9 7" GOSUB 100MAX PRINT R$</lang>
- Output:
20
ARM Assembly
<lang ARM Assembly>
/* ARM assembly Raspberry PI */ /* program rechMax.s */
/* Constantes */ .equ STDOUT, 1 @ Linux output console .equ EXIT, 1 @ Linux syscall .equ WRITE, 4 @ Linux syscall
/*********************************/ /* Initialized data */ /*********************************/ .data szMessResult: .ascii "Max number is = " @ message result sMessValeur: .fill 12, 1, ' '
.ascii " rank = "
sMessRank: .fill 12, 1, ' '
.ascii " address (hexa) = "
sMessAddress: .fill 12, 1, ' '
.asciz "\n"
tTableNumbers: .int 50
.int 12
.int -1000
.int 40
.int 255
.int 60
.int 254
.equ NBRANKTABLE, (. - tTableNumbers) / 4 @ number table posts
/*********************************/ /* UnInitialized data */ /*********************************/ .bss /*********************************/ /* code section */ /*********************************/ .text .global main main: @ entry of program
push {fp,lr} @ saves 2 registers
ldr r1,iAdrtTableNumbers mov r2,#0 ldr r4,[r1,r2,lsl #2] mov r3,r2 add r2,#1
1:
cmp r2,#NBRANKTABLE
bge 2f ldr r0,[r1,r2,lsl #2] cmp r0,r4 movgt r4,r0 movgt r3,r2 add r2,#1 b 1b
2:
mov r0,r4 ldr r1,iAdrsMessValeur bl conversion10S @ call conversion mov r0,r3 ldr r1,iAdrsMessRank bl conversion10 @ call conversion ldr r0,iAdrtTableNumbers add r0,r3,lsl #2 ldr r1,iAdrsMessAddress bl conversion16 @ call conversion ldr r0,iAdrszMessResult bl affichageMess @ display message
100: @ standard end of the program
mov r0, #0 @ return code
pop {fp,lr} @restaur 2 registers
mov r7, #EXIT @ request to exit program
swi 0 @ perform the system call
iAdrtTableNumbers: .int tTableNumbers iAdrsMessValeur: .int sMessValeur iAdrsMessRank: .int sMessRank iAdrsMessAddress: .int sMessAddress iAdrszMessResult: .int szMessResult
/******************************************************************/ /* display text with size calculation */ /******************************************************************/ /* r0 contains the address of the message */ affichageMess:
push {fp,lr} /* save registres */
push {r0,r1,r2,r7} /* save others registers */
mov r2,#0 /* counter length */
1: /* loop length calculation */
ldrb r1,[r0,r2] /* read octet start position + index */
cmp r1,#0 /* if 0 its over */
addne r2,r2,#1 /* else add 1 in the length */
bne 1b /* and loop */
/* so here r2 contains the length of the message */
mov r1,r0 /* address message in r1 */
mov r0,#STDOUT /* code to write to the standard output Linux */
mov r7, #WRITE /* code call system "write" */
swi #0 /* call systeme */
pop {r0,r1,r2,r7} /* restaur others registers */
pop {fp,lr} /* restaur des 2 registres */
bx lr /* return */
/******************************************************************/ /* Converting a register to hexadecimal */ /******************************************************************/ /* r0 contains value and r1 address area */ conversion16:
push {r1-r4,lr} /* save registers */
mov r2,#28 @ start bit position
mov r4,#0xF0000000 @ mask
mov r3,r0 @ save entry value
1: @ start loop
and r0,r3,r4 @value register and mask
lsr r0,r2 @ move right
cmp r0,#10 @ compare value
addlt r0,#48 @ <10 ->digit
addge r0,#55 @ >10 ->letter A-F
strb r0,[r1],#1 @ store digit on area and + 1 in area address
lsr r4,#4 @ shift mask 4 positions
subs r2,#4 @ counter bits - 4 <= zero ?
bge 1b @ no -> loop
@end
pop {r1-r4,lr} @ restaur registres
bx lr @return
/******************************************************************/ /* Converting a register to a decimal */ /******************************************************************/ /* r0 contains value and r1 address area */ conversion10:
push {r1-r4,lr} /* save registers */
mov r3,r1
mov r2,#10
1: @ start loop
bl divisionpar10 @ r0 <- dividende. quotient ->r0 reste -> r1 add r1,#48 @ digit strb r1,[r3,r2] @ store digit on area sub r2,#1 @ previous position cmp r0,#0 @ stop if quotient = 0 */ bne 1b @ else loop @ and move spaves in first on area mov r1,#' ' @ space
2:
strb r1,[r3,r2] @ store space in area subs r2,#1 @ @ previous position bge 2b @ loop if r2 >= zéro
100:
pop {r1-r4,lr} @ restaur registres
bx lr @return
/***************************************************/ /* Converting a register to a signed decimal */ /***************************************************/ /* r0 contains value and r1 area address */ conversion10S:
push {r0-r4,lr} @ save registers
mov r2,r1 /* debut zone stockage */
mov r3,#'+' /* par defaut le signe est + */
cmp r0,#0 @ negative number ?
movlt r3,#'-' @ yes
mvnlt r0,r0 @ number inversion
addlt r0,#1
mov r4,#10 @ length area
1: @ start loop
bl divisionpar10 add r1,#48 @ digit strb r1,[r2,r4] @ store digit on area sub r4,r4,#1 @ previous position cmp r0,#0 @ stop if quotient = 0 bne 1b
strb r3,[r2,r4] @ store signe subs r4,r4,#1 @ previous position blt 100f @ if r4 < 0 -> end
mov r1,#' ' @ space
2:
strb r1,[r2,r4] @store byte space subs r4,r4,#1 @ previous position bge 2b @ loop if r4 > 0
100:
pop {r0-r4,lr} @ restaur registers
bx lr
/***************************************************/ /* division par 10 signé */ /* Thanks to http://thinkingeek.com/arm-assembler-raspberry-pi/* /* and http://www.hackersdelight.org/ */ /***************************************************/ /* r0 dividende */ /* r0 quotient */ /* r1 remainder */ divisionpar10:
/* r0 contains the argument to be divided by 10 */
push {r2-r4} /* save registers */
mov r4,r0
ldr r3, .Ls_magic_number_10 /* r1 <- magic_number */
smull r1, r2, r3, r0 /* r1 <- Lower32Bits(r1*r0). r2 <- Upper32Bits(r1*r0) */
mov r2, r2, ASR #2 /* r2 <- r2 >> 2 */
mov r1, r0, LSR #31 /* r1 <- r0 >> 31 */
add r0, r2, r1 /* r0 <- r2 + r1 */
add r2,r0,r0, lsl #2 /* r2 <- r0 * 5 */
sub r1,r4,r2, lsl #1 /* r1 <- r4 - (r2 * 2) = r4 - (r0 * 10) */
pop {r2-r4}
bx lr /* leave function */
.align 4
.Ls_magic_number_10: .word 0x66666667
</lang>
Arturo
<lang rebol>arr: [5 4 2 9 7 3]
print max arr</lang>
- Output:
9
AutoHotkey
CSV Data
<lang AutoHotkey>list = 1,5,17,-2 Loop Parse, list, `,
x := x < A_LoopField ? A_LoopField : x
MsgBox Max = %x%</lang>
Pseudo-arrays
<lang AHK>list = 1,5,17,-2 StringSplit, list, list,`, ; creates a pseudo-array Loop % List0
x := x < List%A_Index% ? List%A_Index% : x
MsgBox Max = %x%</lang>
True arrays
<lang AHK>List := [1,5,17,-2] For each, value in List
x := x < value ? value : x
MsgBox Max = %x%</lang>
AWK
One-liner: <lang awk>$ awk 'func max(a){for(i in a)if(a[i]>r)r=a[i];return r}BEGIN{a[0]=42;a[1]=33;a[2]=21;print max(a)}' 42</lang>
More readable version: <lang awk>
- Usage: awk -f greatest_list_element.awk
function max(a) {
for(i in a) if(a[i]>r) r=a[i]; return r
}
BEGIN { a[0]=42;
a[1]=33;
a[2]=21;
print max(a)
}
</lang>
Axe
This example assumes the array is null-terminated so that the program can stop at the end of the data. <lang axe>Lbl MAX 0→M While {r₁}
{r₁}>M?{r₁}→M
End M Return</lang>
BASIC
<lang qbasic>DECLARE SUB addVal (value AS INTEGER) DECLARE FUNCTION findMax% ()
REDIM SHARED vals(0) AS INTEGER DIM SHARED valCount AS INTEGER DIM x AS INTEGER, y AS INTEGER
valCount = -1
begin test run RANDOMIZE TIMER FOR x = 1 TO 10
y = INT(RND * 100) addVal y PRINT y; " ";
NEXT PRINT ": "; findMax end test run
SUB addVal (value AS INTEGER)
DIM tmp AS INTEGER
IF valCount > -1 THEN
'this is needed for BASICs that don't support REDIM PRESERVE
REDIM v2(valCount) AS INTEGER
FOR tmp = 0 TO valCount
v2(tmp) = vals(tmp)
NEXT
END IF
valCount = valCount + 1
REDIM vals(valCount)
IF valCount > 0 THEN
'also needed for BASICs that don't support REDIM PRESERVE
FOR tmp = 0 TO valCount - 1
vals(tmp) = v2(tmp)
NEXT
END IF
vals(valCount) = value
END SUB
FUNCTION findMax%
DIM tmp1 AS INTEGER, tmp2 AS INTEGER
FOR tmp1 = 0 TO valCount
IF vals(tmp1) > tmp2 THEN tmp2 = vals(tmp1)
NEXT
findMax = tmp2
END FUNCTION</lang>
- Output:
8162 5139 7004 7393 5151 4476 577 4419 3333 4649 : 8162
BaCon
<lang freebasic>' Greatest element from list ' Populate sample array of numbers READ elements DECLARE numbers TYPE NUMBER ARRAY elements FOR i = 0 TO elements - 1
READ numbers[i]
NEXT DATA 6 DATA 100,-2,300,4,500,6
' Demonstrate the function PRINT greatest(elements, numbers) END
' Return greatest element given count and list of numbers FUNCTION greatest(n, NUMBER a[])
LOCAL mx = a[0]
FOR i = 1 TO n - 1
mx = MAX(mx, a[i])
NEXT
RETURN mx
END FUNCTION</lang>
- Output:
prompt$ ./greatest-element 500
See also: BBC BASIC, Liberty BASIC, PowerBASIC, PureBasic, Run BASIC, TI-89 BASIC, Visual Basic
BASIC256
<lang freebasic>l$ = "1,1234,62,234,12,34,6" dim n$(1) n$ = explode(l$, ",") m$ = "" : m = 0
for i = 1 to n$[?]-1 t$ = n$[i] if t$ > m$ then m$ = t$ if int(t$) > m then m = int(t$) next i
print "Alphabetic order: "; m$; ", numeric order: "; m</lang>
Batch File
<lang dos>::max.cmd @echo off setlocal enabledelayedexpansion set a=.%~1 if "%a%" equ "." set /p a="Input stream: " call :max res %a% echo %res% endlocal goto :eof
- max
set %1=%2
- loop
shift /2 if "%2" equ "" goto :eof if %2 gtr !%1! set res=%2 goto loop</lang>
Invocation from command line or from internal prompt
<lang dos>>max "123 456 3 234243 12" 234243
>max Input stream: 5 4 3 2 67 1 67</lang>
BBC BASIC
<lang bbcbasic> ListOfValues$ = "13, 0, -6, 2, 37, -10, 12"
PRINT "Maximum value = " ; FNmax(ListOfValues$)
END
DEF FNmax(list$)
LOCAL index%, number, max
max = VAL(list$)
REPEAT
index% = INSTR(list$, ",", index%+1)
number = VAL(MID$(list$, index%+1))
IF number > max THEN max = number
UNTIL index% = 0
= max</lang>
bc
<lang bc>define m(a[], n) {
auto m, i
m = a[0]
for (i = 1; i < n; i++) {
if (a[i] > m) m = a[i]
}
return(m)
}</lang>
Befunge
<lang befunge>001pv <
>&:01g`#v_1+#^_01g.@ ^p10 <</lang>
Only works with positive integers. List must be terminated with -1.
BQN
<lang bqn>Max ← ⌈´</lang>
- Output:
Max ¯275‿¯111‿0‿¯1234568‿π‿¯π 3.141592653589793
Bracmat
When comparing two rational numbers, Bracmat compares numerically. In all other cases Bracmat compares lexically. <lang> ( biggest
= max
. !arg:
| !arg:%?max ?arg
& !arg:? (%@:>!max:?max) (?&~)
| !max
)
& out$("1:" biggest$(5 100000 -5 aap 3446 NOOT mies 0)) & out$("2:" biggest$) & out
$ ( "3:"
biggest
$ (5 100000 -5 43756243978569758/13 3365864921428443 87512487957139516/27 3446)
)</lang>
- Output:
1: mies 2: 3: 3365864921428443
Brat
Arrays have a max function, but here's a manual implementation. <lang brat>max = { list |
list.reduce { n, max |
true? n > max
{ max = n }
{ max }
}
}
p max [3 4 1 2]</lang>
Burlesque
<lang burlesque> blsq ) {88 99 77 66 55}>] 99 </lang>
C
This works well with floats. Replace with double, int or what-have-you before passing a different data type. <lang c>#include <assert.h>
float max(unsigned int count, float values[]) {
assert(count > 0);
size_t idx;
float themax = values[0];
for(idx = 1; idx < count; ++idx) {
themax = values[idx] > themax ? values[idx] : themax;
}
return themax;
}</lang>
The following macro can be used with any number and type of arguments, provided that the arguments are simple, i.e. must not contain subexpressions where commas appear (this is because of the way the arguments are counted; the macro can be modified so that it is up to the caller to count the number of arguments passed).
<lang c>#include <stdarg.h>
- define MAX(A,...) ({ inline __typeof__ (A) _max_(__typeof__ (A) a, ...) {\
va_list l; int i,c; const char *s = #__VA_ARGS__; __typeof__ (A) max = a;\
__typeof__ (A) t;\
for(c=1;*s!=0;s++) if (*s==',') c++;\
va_start(l, a);\
for(i=0;i<=c;i++) {\
if ((t=va_arg(l,__typeof__ (A))) > max) max = t;\
}\
va_end(l); return max;\
}\ _max_((A),__VA_ARGS__);\ })</lang>
C#
C# already has a "Maximum Value" function.
<lang csharp>int[] values = new int[] {1,2,3,4,5,6,7,8,9,10};
int max = values.Max();</lang>
C++
A simple wrapper around the standard library function max_element(). Requires C++17. <lang cpp>#include <algorithm> //std::max_element
- include <iterator> //std::begin and std::end
- include <functional> //std::less
template<class It, class Comp = std::less<>>
//requires ForwardIterator<It> && Compare<Comp>
constexpr auto max_value(It first, It last, Comp compare = std::less{}) {
//Precondition: first != last return *std::max_element(first, last, compare);
}
template<class C, class Comp = std::less<>>
//requires Container<C> && Compare<Comp>
constexpr auto max_value(const C& container, Comp compare = std::less{}) {
//Precondition: !container.empty() using std::begin; using std::end; return max_value(begin(container), end(container), compare);
}</lang>
CFEngine
Note: CFEngine bundles are NOT functions, however they can behave in some ways that are similar to functions.
<lang cfengine3> bundle agent __main__ {
vars:
"number_of_list_elements"
int => randomint( "0", 100 ),
unless => isvariable( "$(this.promiser)" );
"idx"
slist => expandrange( "[0-$(number_of_list_elements)]", 1 ),
unless => isvariable( "$(this.promiser)" );
"number[$(idx)]"
int => randomint( "0", "100" ),
unless => isvariable( "$(this.promiser)" );
"numbers" slist => sort( getvalues( number ), int );
methods:
"Get the greatest value"
usebundle => greatest_value( @(numbers) ),
useresult => "returned";
reports:
"'$(returned[max])' is the largest number in $(with)"
with => join( ",", numbers );
}
bundle agent greatest_value(list_of_values)
{
reports:
"$(with)"
with => max( list_of_values, int ),
bundle_return_value_index => "max";
} </lang>
- Output:
R: '97' is the largest number in 3,5,6,13,15,30,34,37,47,49,49,53,54,59,59,59,60,62,64,67,78,83,95,97
Clojure
The Clojure.core function max returns the max of its arguments. <lang clojure>(max 1 2 3 4) ; evaluates to 4
- If the values are already in a collection, use apply
(apply max [1 2 3 4]) ; evaluates to 4</lang>
CLU
<lang clu>% This "maximum" procedure is fully general, as long as % the container type has an elements iterator and the % data type is comparable. % It raises an exception ("empty") if there are no elements.
maximum = proc [T,U: type] (a: T) returns (U)
signals (empty)
where T has elements: itertype (T) yields (U),
U has gt: proctype (U,U) returns (bool)
max: U
seen: bool := false
for item: U in T$elements(a) do
if ~seen cor item > max then
max := item
seen := true
end
end
if (~seen) then
signal empty
else
return(max)
end
end maximum
start_up = proc ()
po: stream := stream$primary_output() % try it on an array of ints ints: array[int] := array[int]$[1,5,17,2,53,99,61,3] imax: int := maximum[array[int], int](ints) stream$putl(po, "maximum int: " || int$unparse(imax))
% try it on a sequence of reals reals: sequence[real] := sequence[real]$[-0.5, 2.6, 3.14, 2.72] rmax: real := maximum[sequence[real], real](reals) stream$putl(po, "maximum real: " || real$unparse(rmax))
end start_up</lang>
- Output:
maximum int: 99 maximum real: 3.140000e+00
CMake
Only for lists of integers.
<lang cmake># max(var [value1 value2...]) sets var to the maximum of a list of
- integers. If list is empty, sets var to NO.
function(max var)
set(first YES)
set(choice NO)
foreach(item ${ARGN})
if(first)
set(choice ${item})
set(first NO)
elseif(choice LESS ${item})
set(choice ${item})
endif()
endforeach(item)
set(${var} ${choice} PARENT_SCOPE)
endfunction(max)
set(list 33 11 44 22 66 55) max(maximum ${list}) message(STATUS "maximum of ${list} => ${maximum}")</lang>
-- maximum of 33;11;44;22;66;55 => 66
COBOL
This is already built into the language for tables of numbers. <lang cobol>DISPLAY FUNCTION MAX(nums (ALL))</lang>
A sample implementation: <lang cobol> IDENTIFICATION DIVISION.
FUNCTION-ID. greatest-elt.
DATA DIVISION.
LOCAL-STORAGE SECTION.
01 idx USAGE INDEX.
01 Table-Len CONSTANT 50.
LINKAGE SECTION.
01 num-table-area.
03 num-table PIC 9(8) OCCURS Table-Len TIMES.
01 max-elt PIC 9(8).
PROCEDURE DIVISION USING VALUE num-table-area RETURNING max-elt.
PERFORM VARYING idx FROM 1 BY 1 UNTIL idx > Table-Len
IF num-table (idx) > max-elt
MOVE num-table (idx) TO max-elt
END-IF
END-PERFORM
GOBACK
.
END FUNCTION greatest-elt.</lang>
CoffeeScript
<lang coffeescript>
- using Math library
max1 = (list) ->
Math.max.apply null, list
- using no libraries
max2 = (list) ->
maxVal = list[0] for value in list maxVal = value if value > maxVal maxVal
- Test it
a = [0,1,2,5,4]; alert(max1(a)+". The answer is "+max2(a)); </lang>
ColdFusion
<lang cfm> <Cfset theList = '1, 1000, 250, 13'> <Cfparam name="maxNum" default=0> <Cfloop list="#theList#" index="i">
<Cfif i gt maxNum><Cfset maxNum = i></Cfif>
</Cfloop> <Cfoutput>#maxNum#</Cfoutput> </lang>
<lang cfm> <Cfset theList = '1, 1000, 250, 13'> <Cfset maxNum = ListFirst(ListSort(thelist, "numeric", "desc"))> <Cfoutput>#maxNum#</Cfoutput> </lang>
Common Lisp
The built-in Common Lisp function max takes the max of all its arguments. <lang lisp>(max 1 2 3 4) (reduce #'max values) ; find max of a list (loop for x in values
maximize x) ; alternative way to find max of a list</lang>
Component Pascal
BalckBox Component Builder <lang oberon2> MODULE Operations; IMPORT StdLog,Args,Strings;
PROCEDURE Max(s: ARRAY OF INTEGER): INTEGER; VAR i: INTEGER; max: INTEGER; BEGIN max := MIN(INTEGER); FOR i := 0 TO LEN(s) - 1 DO max := MAX(max,s[i]); END; RETURN max END Max;
PROCEDURE DoMax*; VAR sq: POINTER TO ARRAY OF INTEGER; p: Args.Params; i,n,done: INTEGER; BEGIN Args.Get(p); IF p.argc > 0 THEN NEW(sq,p.argc); FOR i := 0 TO p.argc - 1 DO Strings.StringToInt(p.args[i],n,done); sq[i] := n END; StdLog.String("max:> ");StdLog.Int(Max(sq));StdLog.Ln END END DoMax;
END Operations.
</lang>
Execute: ^Q Operations..DoMax 23 12 3 45 34 54 84 ~
- Output:
max:> 84
Crystal
<lang ruby>values.max</lang>
D
D already has a "Maximum Element" function.
<lang d>void main() {
import std.algorithm.searching : maxElement; import std.stdio : writeln;
[9, 4, 3, 8, 5].maxElement.writeln;
}</lang>
- Output:
9
Dart
<lang Dart>/*This is a function which returns the greatest element in a list of numbers */ num findGreatestElement(List<num> list){
num greatestElement = list[0];
for (num element in list){
if (element>greatestElement) {
greatestElement = element;
}
}
return greatestElement;
} /* and this is a shorter version */ import 'dart:math'; num findGreatestElement(List<num> list){
return list.reduce(max);
} </lang>
dc
<lang dc>[sm llx] sg [lm p q] sq [d lm <u s_ z 0 =q llx] sl [d sm] su
["Put list of numbers on the stack starting here, then execute g"] s_
3.14159265358979 sp
_275.0 _111.19 0.0 _1234568.0 lp lp _1 *
lgx</lang>
- Output:
3.14159265358979
DCL
<lang DCL>$ list = "45,65,81,12,0,13,-56,123,-123,888,12,0" $ max = f$integer( f$element( 0, ",", list )) $ i = 1 $ loop: $ element = f$element( i, ",", list ) $ if element .eqs. "," then $ goto done $ element = f$integer( element ) $ if element .gt. max then $ max = element $ i = i + 1 $ goto loop $ done: $ show symbol max</lang>
- Output:
$ @greatest MAX = 888 Hex = 00000378 Octal = 00000001570
Delphi
<lang Delphi> program GElemLIst; {$IFNDEF FPC}
{$Apptype Console}
{$ENDIF}
uses
math;
const
MaxCnt = 10000;
var
IntArr : array of integer; fltArr : array of double; i: integer;
begin
setlength(fltArr,MaxCnt); //filled with 0 setlength(IntArr,MaxCnt); //filled with 0.0 randomize; i := random(MaxCnt); //choose a random place IntArr[i] := 1; fltArr[i] := 1.0; writeln(Math.MaxIntValue(IntArr)); // Array of Integer writeln(Math.MaxValue(fltArr));
end. </lang>
Dyalect
<lang dyalect>func max(xs) {
var y
for x in xs {
if y == nil || x > y {
y = x
}
}
y
}
var xs = [1..10] max(xs)</lang>
Déjà Vu
<lang dejavu>max lst:
lst! 0
for item in copy lst:
if > item dup:
item drop
!. max [ 10 300 999 9 ]</lang>
- Output:
999
Draco
<lang draco>/* Find the greatest element in an array of ints */ proc nonrec max([*] int a) int:
int INT_MIN = ~((~0) >> 1);
int nmax, i;
nmax := INT_MIN;
for i from 0 upto dim(a,1)-1 do
if a[i] > nmax then nmax := a[i] fi
od;
nmax
corp
/* Test on an array */ proc nonrec main() void:
type arr = [8] int;
writeln("Maximum: ", max(arr(1,5,17,2,53,99,61,3)))
corp</lang>
- Output:
Maximum: 99
E
This function works for any value which responds to max/1:
<lang e>pragma.enable("accumulator") # non-finalized syntax feature
def max([first] + rest) {
return accum first for x in rest { _.max(x) }
}</lang>
<lang e>? max([1, 2, 3])
- value: 3</lang>
To require only the comparison protocol, one needs to write out the algorithm a little more explicitly:
<lang e>def max([var bestSoFar] + rest) {
for x ? (x > bestSoFar) in rest {
bestSoFar := x
}
return bestSoFar
}</lang>
<lang e>? max([1, 3, 2])
- value: 3
? max([[1].asSet(), [2].asSet(), [1, 2].asSet()])
- value: [1, 2].asSet()</lang>
EasyLang
<lang>a[] = [ 2 9 4 3 8 5 ] for e in a[]
max = higher e max
. print max</lang>
EchoLisp
<lang lisp>
- a random length list of random values
(define L (map random (make-list (random 50) 100))) → L L → (24 60 83 8 24 60 31 97 96 65 9 41 64 24 22 57 73 17 6 28 77 58 18 13 27 22 41 69 85)
- find max
(apply max L) → 97 </lang>
ECL
<lang ECL> MaxVal(SET OF INTEGER s) := MAX(s);
//example usage
SetVals := [4,8,16,2,1]; MaxVal(SetVals) //returns 16; </lang>
Efene
<lang efene>list_max = fn ([Head:Rest]) {
list_max(Rest, Head)
}
list_max = fn ([], Res) {
Res
} fn ([Head:Rest], Max) when Head > Max {
list_max(Rest, Head)
} fn ([_Head:Rest], Max) {
list_max(Rest, Max)
}
list_max1 = fn ([H:T]) {
lists.foldl(fn erlang.max:2, H, T)
}
@public run = fn () {
io.format("~p~n", [list_max([9, 4, 3, 8, 5])])
io.format("~p~n", [list_max1([9, 4, 3, 8, 5])])
} </lang>
Eiffel
The GREATEST_ELEMENT class: <lang eiffel> class GREATEST_ELEMENT [G -> COMPARABLE]
create make
feature {NONE} --Implementation
is_max (element: G maximum: G): BOOLEAN do Result := maximum >= element end
max (list: ARRAY [G]): G require not_empty: not list.is_empty do Result := list [list.lower] across list as i loop Result := i.item.max (Result) end ensure is_part_of_array: list.has (Result) is_maximum: list.for_all (agent is_max(?, Result)) end
feature -- Initialization
make do end
greatest_element (a: ARRAY [G]): G do Result := max (a) end
end </lang> A test application: <lang eiffel> class APPLICATION
create make
feature {NONE} -- Initialization
make -- Run application. local numbers: ARRAY [INTEGER] greatest: GREATEST_ELEMENT [INTEGER] do create greatest.make numbers := <<1, 2, 3, 4, 5, 6, 7, 8, 9>> print (greatest.greatest_element (numbers)) end
end </lang>
Ela
<lang ela>open list
findBy p (x::xs) = foldl (\x y | p x y -> x | else -> y) x xs maximum = findBy (>)
maximum [1..10]</lang>
Elena
ELENA 5.0 : <lang elena>import extensions;
extension op {
get Maximal()
{
auto en := cast Enumerator(self.enumerator());
object maximal := nil;
while (en.next())
{
var item := en.get();
if (nil == maximal)
{
maximal := item
}
else if (maximal < item)
{
maximal := item
}
};
^ maximal
}
}
public program() {
console.printLine(new int[]{1,2,3,4,20,10,9,8}.Maximal)
}</lang>
- Output:
20
Elixir
<lang elixir>iex(1)> Enum.max([3,1,4,1,5,9,2,6,5,3]) 9</lang>
Emacs Lisp
<lang lisp>(defun find-maximum (items)
(let (max)
(dolist (item items)
(when (or (not max) (> item max))
(setq max item)))
max))
(find-maximum '(2 7 5)) ;=> 7</lang>
Built-in:
<lang lisp>(max '(2 7 5)) ;=> 7</lang>
<lang lisp>(cl-loop for el in '(2 7 5) maximize el) ;=> 7 (cl-reduce #'max '(2 7 5)) ;=> 7</lang>
<lang lisp>(seq-max '(2 7 5)) ;=> 7</lang>
Erlang
Builtin. Using it from the Erlang shell: <lang erlang>>lists:max([9,4,3,8,5]). 9</lang>
ERRE
<lang ERRE> PROGRAM MAXLIST
! ! for rosettacode.org !
! VAR L$,EL$,CH$,I%,MAX
BEGIN
PRINT(CHR$(12);) ! CLS
INPUT("Lista",L$)
L$=L$+CHR$(32)
MAX=-1.7E+38
FOR I%=1 TO LEN(L$) DO
CH$=MID$(L$,I%,1)
IF CH$<>CHR$(32) THEN ! blank is separator
EL$=EL$+CH$
ELSE
IF VAL(EL$)>MAX THEN MAX=VAL(EL$) END IF
EL$=""
END IF
END FOR
PRINT("Max list element is";MAX)
END PROGRAM </lang> Note: The limit of this program is string variable lenght (255 chars). The advantage is no array use.
Euler Math Toolbox
<lang> >v=random(1,100); >max(v)
0.997492478596
</lang>
Euphoria
Applying a function to each element of an array
<lang Euphoria>function aeval( sequence sArr, integer id )
for i = 1 to length( sArr ) do
sArr[ i ] = call_func( id, { sArr[ i ] } )
end for
return sArr
end function
object biggun function biggest( object elem )
if compare(elem, biggun) > 0 then
biggun = elem
end if
return elem
end function
biggun = 0 object a a = aeval( {1,1234,62,234,12,34,6}, routine_id("biggest") ) printf( 1, "%d\n", biggun )
sequence s s = {"antelope", "dog", "cat", "cow", "wolf", "wolverine", "aardvark"} biggun = "ant" a = aeval( s, routine_id("biggest") ) printf( 1, "%s\n", {biggun} )</lang>
- Output:
1234 wolverine
More trivial example
<lang euphoria>function get_biggest(sequence s)
object biggun
biggun = s[1]
for i = 2 to length(s) do
if compare(s[i], biggun) > 0 then
biggun = s[i]
end if
end for
return biggun
end function
constant numbers = {1,1234,62,234,12,34,6} printf(1,"%d\n",get_biggest(numbers))
constant animals = {"ant", "antelope", "dog", "cat", "cow", "wolf", "wolverine", "aardvark"} printf(1,"%s\n",{get_biggest(animals)})</lang>
- Output:
1234 wolverine
Excel
Use the function MAX
<lang Excel> =MAX(3;2;1;4;5;23;1;2) </lang>
- Output:
23
F#
I generate a list of 10 random numbers at runtime then use F#'s built in function to find the maximum value of the list.
<lang fsharp> let N = System.Random() let G = List.init 10 (fun _->N.Next()) List.iter (printf "%d ") G printfn "\nMax value of list is %d" (List.max G) </lang>
- Output:
401566008 1378437959 1806806326 2010005455 1973773308 1216833747 268836584 1963610340 2120237482 1412806752 Max value of list is 2120237482
Factor
The following word is in factor's standard library. <lang factor>: supremum ( seq -- elt ) [ ] [ max ] map-reduce ;</lang>
Fancy
<lang fancy>[1,-2,2,4,6,-4,-1,5] max println # => 6</lang>
Fantom
Has a built-in method to get maximum from a list.
<lang fantom> class Greatest {
public static Void main ()
{
Int[] values := [1,2,3,4,5,6,7,8,9]
Int greatest := values.max
echo (greatest)
}
} </lang>
Forth
<lang forth>: array-max ( addr len -- max )
dup 0= if nip exit then over @ rot cell+ rot 1- cells bounds ?do i @ max cell +loop ;
- stack-max ( n ... m count -- max ) 1 ?do max loop ;</lang>
Fortran
The intrinsic function maxval returns the maximum value of the elements in an integer or real array:
<lang fortran>program test_maxval
integer,dimension(5),parameter :: x = [10,100,7,1,2] real,dimension(5),parameter :: y = [5.0,60.0,1.0,678.0,0.0]
write(*,'(I5)') maxval(x) write(*,'(F5.1)') maxval(y)
end program test_maxval</lang>
- Output:
100 678.0
The intrinsic function max accepts any number of arguments. The type of these arguments can be integer, real, character, string of characters or arrays of these. <lang fortran>program test_max
implicit none
write (*, '(i0)') &
& max (1, 2, 3)
write (*, '(f3.1)') &
& max (1.0, 2.0, 3.0)
write (*, '(a)') &
& max ('a', 'b', 'c')
write (*, '(a)') &
& max ('abc', 'bca', 'cab')
write (*, '(i0, 2 (1x, i0))') &
& max ([1, 8, 6], [7, 5, 3], [4, 2, 9])
write (*, '(f3.1, 2 (1x, f3.1))') &
& max ([1.0, 8.0, 6.0], [7.0, 5.0, 3.0], [4.0, 2.0, 9.0])
write (*, '(a, 2 (1x, a))') &
& max (['a', 'h', 'f'], ['g', 'e', 'c'], ['d', 'b', 'i'])
write (*, '(a, 2 (1x, a))') &
& max (['abc', 'hig', 'fde'], ['ghi', 'efd', 'cab'], ['def', 'bca', 'igh'])
end program test_max</lang>
- Output:
3 3.0 c cab 7 8 9 7.0 8.0 9.0 g h i ghi hig igh
FreeBASIC
<lang freebasic>' FB 1.05.0 Win64
Function MaxElement(a() As Double) As Double
Dim max As Double = a(LBound(a)) For i As Integer = LBound(a) + 1 To UBound(a) If a(i) > max Then max = a(i) Next Return max
End Function
Dim As Integer i, n Input "How many values are to be input "; n If n < 1 Then End Dim a(1 To n) As Double For i = 1 To n
Print " Value"; i; " : "; Input "", a(i)
Next Dim max As Double = MaxElement(a()) Print Print "The greatest value is"; max Print Print "Press any key to quit" Sleep </lang>
Example of use :
- Output:
How many values are to be input ? 4 Value 1 : 70.5 Value 2 : 23.67 Value 3 : 150.2 Value 4 : 145 The greatest value is 150.2
Frink
<lang frink> println[max1,2,3,5,10,20] </lang>
FunL
Using the pre-defined function max:
<lang funl>println( max([1,2,3,-1,0]) )</lang>
- Output:
3
It can be implemented as: <lang funl>def
maximum( xs ) =
def
max( a, b ) = if a <= b then b else a
foldl( f, z, [] ) = z
foldl( f, z, x:xs ) = foldl( f, f(z, x), xs )
foldl1( f, x:xs ) = foldl( f, x, xs )
foldl1( _, [] ) = error( "foldl1: empty list" )
foldl1( max, xs )</lang>
Futhark
<lang futhark>let main (xs: []f64) = reduce f64.max (-f64.inf) xs</lang>
This parallel formulation exploits the fact that negative infinity constitutes a neutral element for the maximum operator.
Fōrmulæ
Fōrmulæ programs are not textual, visualization/edition of programs is done showing/manipulating structures but not text. Moreover, there can be multiple visual representations of the same program. Even though it is possible to have textual representation —i.e. XML, JSON— they are intended for storage and transfer purposes more than visualization and edition.
Programs in Fōrmulæ are created/edited online in its website, However they run on execution servers. By default remote servers are used, but they are limited in memory and processing power, since they are intended for demonstration and casual use. A local server can be downloaded and installed, it has no limitations (it runs in your own computer). Because of that, example programs can be fully visualized and edited, but some of them will not run if they require a moderate or heavy computation/memory resources, and no local server is being used.
In this page you can see the program(s) related to this task and their results.
GW-BASIC
<lang gwbasic>10 INPUT "How many items? ", N% 20 DIM ARR(N%) 30 FOR I% = 0 TO N%-1 40 PRINT "Value of item #";I% 50 INPUT ARR(I%) 60 NEXT I% 70 CHAMP = ARR(0) : INDEX = 0 80 FOR I% = 1 TO N%-1 90 IF ARR(I%)>CHAMP THEN CHAMP=ARR(I%):INDEX=I% 100 NEXT I% 110 PRINT "The maximum value was ";CHAMP;" at index ";INDEX;"." 120 END</lang>
GAP
<lang gap># Built-in
L := List([1 .. 100], n -> Random(1, 10));
MaximumList(L);
- 10</lang>
Go
- Library
-
- <lang go>package main
import (
"fmt"
"github.com/gonum/floats"
)
func main() { fmt.Println(floats.Max([]float64{63, 70, 37, 34, 83, 27, 19, 97, 9, 17})) // prt 97 fmt.Println(floats.Min([]float64{63, 70, 37, 34, 83, 27, 19, 97, 9, 17})) // prt 9 }</lang>
- <lang go>package main
import "fmt"
func main() { x := []int{ 48, 96, 86, 68, 57, 82, 63, 70, 37, 34, 83, 27, 19, 97, 9, 17, }
smallest, biggest := x[0], x[0] for _, v := range x { if v > biggest { biggest = v } if v < smallest { smallest = v } }
fmt.Println("The biggest number is ", biggest) // prt 97 fmt.Println("The smallest number is ", smallest) // prt 9 }</lang>
- List
The task title says list. This solution uses a Go slice as a list. <lang go>package main
import (
"fmt" "math/rand" "time"
)
// function, per task description func largest(a []int) (lg int, ok bool) {
if len(a) == 0 {
return
}
lg = a[0]
for _, e := range a[1:] {
if e > lg {
lg = e
}
}
return lg, true
}
func main() {
// random size slice
rand.Seed(time.Now().UnixNano())
a := make([]int, rand.Intn(11))
for i := range a {
a[i] = rand.Intn(101) - 100 // fill with random numbers
}
fmt.Println(a)
lg, ok := largest(a)
if ok {
fmt.Println(lg)
} else {
fmt.Println("empty list. no maximum.")
}
}</lang>
- Set
The task description says set. This solution uses a Go map as a set. <lang go>package main
import (
"fmt" "math" "math/rand" "time"
)
// Function, per task description. Interesting with the float64 type because // of the NaN value. NaNs do not compare to other values, so the result of // a "largest" function on a set containing a NaN might be open to // interpretation. The solution provided here is to return the largest // of the non-NaNs, and also return a bool indicating the presense of a NaN. func largest(s map[float64]bool) (lg float64, ok, nan bool) {
if len(s) == 0 {
return
}
for e := range s {
switch {
case math.IsNaN(e):
nan = true
case !ok || e > lg:
lg = e
ok = true
}
}
return
}
func main() {
rand.Seed(time.Now().UnixNano())
// taking "set" literally from task description
s := map[float64]bool{}
// pick number of elements to add to set
n := rand.Intn(11)
// add random numbers, also throw in an occasional NaN or Inf.
for i := 0; i < n; i++ {
switch rand.Intn(10) {
case 0:
s[math.NaN()] = true
case 1:
s[math.Inf(1)] = true
default:
s[rand.ExpFloat64()] = true
}
}
fmt.Print("s:")
for e := range s {
fmt.Print(" ", e)
}
fmt.Println()
switch lg, ok, nan := largest(s); {
case ok && !nan:
fmt.Println("largest:", lg)
case ok:
fmt.Println("largest:", lg, "(NaN present in data)")
case nan:
fmt.Println("no largest, all data NaN")
default:
fmt.Println("no largest, empty set")
}
}</lang>
Golfscript
<lang golfscript>{$-1=}:max; [1 4 8 42 6 3]max # Example usage</lang>
Groovy
<lang groovy>println ([2,4,0,3,1,2,-12].max())</lang>
- Output:
4
Haskell
The built-in Haskell function maximum returns a maximum based on default comparison between members of an ordered type. <lang haskell>my_max = maximum</lang> It can alternately be defined as a "fold" on the built-in two-argument max function. <lang haskell>my_max = foldl1 max</lang>
More generally, maximum is a special case of maximumBy, which allows us to define or supply our own comparison function, and define the particular type of maximum that we need: <lang haskell>import Data.List (maximumBy) import Data.Ord (comparing)
wds :: [String] wds = ["alpha", "beta", "gamma", "delta", "epsilon", "zeta"]
main :: IO () main = print $ maximumBy (comparing length) wds</lang>
As a fold, maximumBy could be defined along the lines of:
<lang haskell>maximumBy
:: Foldable t => (a -> a -> Ordering) -> t a -> a
maximumBy cmp =
let max_ x y =
case cmp x y of
GT -> x
_ -> y
in foldr1 max_</lang>
hexiscript
<lang hexiscript>fun greatest a
let l len a
let max a[0]
for let i 1; i < l; i++
if max < a[i]
let max a[i]
endif
endfor
return max
endfun</lang>
HicEst
<lang hicest>
max_value = MAX( -123, 234.56, 345.678, -456E3, -455) ! built-in function MAX(...)
! or for an array:
max_value = MAX( array_of_values )
! or to find a maximum value in a file named filename:
CHARACTER List, filename='Greatest element of a list.hic' ! filename contains this script REAL values(1) ! unknown number of values, allocate more below
OPEN(FIle=filename, BINary, LENgth=len) ALLOCATE(values, len/2) ! number of values <= half byte count of file ! read all values, returns item count in values_found: READ(FIle=filename, ItemS=values_found, CLoSe=1) values ! no Format needed for plain text numbers
max_value = MAX(values)
! write values found in filename and result to spreadsheet type dialog window: DLG(Text=values, Text=max_value, TItle=values_found)
WRITE(ClipBoard, Name) max_value, values_found, values ! pasted to line below ! max_value=345.678; values_found=30; values(1)=-123; values(2)=234.56; values(3)=345.678; values(4)=-456E3; values(5)=-455; values(6)=1; values(7)=2; values(8)=1; values(9)=0; values(10)=0; ...truncated END
</lang>
Hoon
<lang Hoon>:- %say |= [^ [a=(list ,@) ~] ~]
- - %noun
(snag 0 (sort a gte))</lang>
Usage: Add to a file gen/max.hoon
> +max [1 2 3 ~] 3
i
<lang i>concept largest(l) { large = l[0] for element in l if element > large large = element end end return large }
software { print(largest([23, 1313, 21, 35757, 4, 434, 232, 2, 2342])) }</lang>
Icon and Unicon
<lang icon>procedure main()
local l l := [7,8,6,9,4,5,2,3,1] write(max(l))
end
procedure max(l)
local max max := l[1] every max <:= !l return max
end</lang>
IS-BASIC
<lang IS-BASIC>1000 DEF FINDMAX(REF ARR) 1010 LET MX=ARR(LBOUND(ARR)) 1020 FOR I=LBOUND(ARR)+1 TO UBOUND(ARR) 1030 LET MX=MAX(MX,ARR(I)) 1040 NEXT 1050 LET FINDMAX=MX 1060 END DEF</lang>
J
Solution:<lang j> >./</lang> Example:<lang J> >./ 1 2 3 2 1 3
>./ NB. Maximum value of an empty list = identity element (or neutral) of max = -∞
__</lang>
Janet
<lang janet> (def elems @[3 1 3 2])
- Use extreme function from stdlib with > function.
(extreme > elems)
- Unpack list as arguments to max function.
(max ;elems) </lang>
Java
The first function works with arrays of floats. Replace with arrays of double, int, or other primitive data type. <lang java>public static float max(float[] values) throws NoSuchElementException {
if (values.length == 0)
throw new NoSuchElementException();
float themax = values[0];
for (int idx = 1; idx < values.length; ++idx) {
if (values[idx] > themax)
themax = values[idx];
}
return themax;
}</lang>
Optionally, if it is OK to rearrange the contents of the original array: <lang java>public static float max(float[] values) throws NoSuchElementException {
if (values.length == 0)
throw new NoSuchElementException();
Arrays.sort(values);//sorts the values in ascending order
return values[values.length-1];
}</lang>
The following functions work with Lists or arrays of reference types, respectively. Note that the type is required to implement Comparable, to ensure we can compare them. For Lists, there is a utility method Collections.max() that already does this. For arrays, we can just use the Arrays.asList() wrapper to wrap it into a list and then use the function for lists. <lang java>import java.util.List; import java.util.Collections; import java.util.Arrays;
public static <T extends Comparable<? super T>> T max(List<T> values) {
return Collections.max(values);
}
public static <T extends Comparable<? super T>> T max(T[] values) {
return Collections.max(Arrays.asList(values));
}</lang>
JavaScript
ES3-5
<lang javascript>Math.max.apply(null, [ 0, 1, 2, 5, 4 ]); // 5</lang>
ES 5 maxima beyond simple numeric data types
Math.max() serves well with simple numeric types, but for less restricted use we can write a generic maximumBy function which returns the maximum value from an array containing a series of any consistent data type, and which takes a type-specific comparison function as an argument.
<lang JavaScript>(function () {
// (a -> a -> Ordering) -> [a] -> a
function maximumBy(f, xs) {
return xs.reduce(function (a, x) {
return a === undefined ? x : (
f(x, a) > 0 ? x : a
);
}, undefined);
}
// COMPARISON FUNCTIONS FOR SPECIFIC DATA TYPES
//Ordering: (LT|EQ|GT) // GT: 1 (or other positive n) // EQ: 0 // LT: -1 (or other negative n)
function wordSortFirst(a, b) {
return a < b ? 1 : (a > b ? -1 : 0)
}
function wordSortLast(a, b) {
return a < b ? -1 : (a > b ? 1 : 0)
}
function wordLongest(a, b) {
return a.length - b.length;
}
function cityPopulationMost(a, b) {
return a.population - b.population;
}
function cityPopulationLeast(a, b) {
return b.population - a.population;
}
function cityNameSortFirst(a, b) {
var strA = a.name,
strB = b.name;
return strA < strB ? 1 : (strA > strB ? -1 : 0); }
function cityNameSortLast(a, b) {
var strA = a.name,
strB = b.name;
return strA < strB ? -1 : (strA > strB ? 1 : 0); }
var lstWords = [
'alpha', 'beta', 'gamma', 'delta', 'epsilon', 'zeta', 'eta',
'theta', 'iota', 'kappa', 'lambda'
];
var lstCities = [
{
name: 'Shanghai',
population: 24.15
}, {
name: 'Karachi',
population: 23.5
}, {
name: 'Beijing',
population: 21.5
}, {
name: 'Tianjin',
population: 14.7
}, {
name: 'Istanbul',
population: 14.4
}, , {
name: 'Lagos',
population: 13.4
}, , {
name: 'Tokyo',
population: 13.3
}
];
return [
maximumBy(wordSortFirst, lstWords),
maximumBy(wordSortLast, lstWords),
maximumBy(wordLongest, lstWords),
maximumBy(cityPopulationMost, lstCities),
maximumBy(cityPopulationLeast, lstCities),
maximumBy(cityNameSortFirst, lstCities),
maximumBy(cityNameSortLast, lstCities)
]
})();</lang>
- Output:
<lang JavaScript>[
"alpha",
"zeta",
"epsilon",
{
"name": "Shanghai",
"population": 24.15
},
{
"name": "Tokyo",
"population": 13.3
},
{
"name": "Beijing",
"population": 21.5
},
{
"name": "Tokyo",
"population": 13.3
}
]</lang>
ES6
For, numbers, a method of the standard Math object: <lang javascript>Math.max(...[ 0, 1, 2, 5, 4 ]); // 5</lang>
and for orderings defined over other datatypes: <lang JavaScript>(() => {
"use strict";
// ----------- GREATEST ELEMENT OF A LIST ------------
// maximumByMay :: (a -> a -> Ordering) ->
// [a] -> Maybe a
const maximumByMay = f =>
// Nothing, if the list is empty,
// or just the maximum value when compared
// in terms of f.
xs => Boolean(xs.length) ? (
Just(xs.slice(1).reduce(
(a, x) => 0 < f(a)(x) ? (
a
) : x,
xs[0]
))
) : Nothing();
// ---------------------- TEST -----------------------
const main = () =>
JSON.stringify(
catMaybes([
maximumByMay(
comparing(x => x.length)
)([
"alpha", "beta", "gamma", "delta",
"epsilon", "zeta", "eta"
]),
maximumByMay(comparing(x => x.length))([]),
maximumByMay(comparing(x => x.n))([{
k: "Bejing",
n: 21.5
}, {
k: "Delhi",
n: 16.7
}, {
k: "Karachi",
n: 23.5
}, {
k: "Lagos",
n: 16.0
}, {
k: "Shanghai",
n: 24.3
}, {
k: "Tokyo",
n: 13.2
}])
]),
null, 2
);
// --------------------- GENERIC ---------------------
// Just :: a -> Maybe a
const Just = x => ({
type: "Maybe",
Nothing: false,
Just: x
});
// Nothing :: Maybe a
const Nothing = () => ({
type: "Maybe",
Nothing: true
});
// catMaybes :: [Maybe a] -> [a]
const catMaybes = mbs =>
mbs.flatMap(
m => m.Nothing ? (
[]
) : [m.Just]
);
// comparing :: (a -> b) -> (a -> a -> Ordering)
const comparing = f =>
x => y => {
const
a = f(x),
b = f(y);
return a < b ? -1 : (a > b ? 1 : 0);
};
// MAIN --- return main();
})();</lang>
- Output:
[
"epsilon",
{
"k": "Shanghai",
"n": 24.3
}
]
jq
jq defines a total ordering of all JSON entities, and the max filter can accordingly be used on any JSON array: <lang jq>[1, 3, 1.0] | max # => 3
[ {"a": 1}, {"a":3}, {"a":1.0}] | max # => {"a": 3}</lang> Warning: both "[null]|max" and "[]|max" yield null.
Given a stream, s, of JSON values, the following filter will emit null if the stream is empty, or the maximum value otherwise: <lang jq>reduce s as $x (null; if $x > . then $x else . end)</lang>
Julia
Using the built-in maximum function:
<lang julia>julia> maximum([1,3,3,7])
7
julia> maximum([pi,e+2/5,cos(6)/5,sqrt(91/10)]) 3.141592653589793
julia> maximum([1,6,Inf]) Inf
julia> maximum(Float64[]) maximum: argument is empty at In[138]:1
in maximum at abstractarray.jl:1591
</lang> (Note that it throws an exception on an empty array.)
K
<lang k> |/ 6 1 7 4 7</lang>
Klingphix
<lang Klingphix>include ..\Utilitys.tlhy
( "1" "1234" "62" "234" "12" "34" "6" )
dup "Alphabetic order: " print lmax ?
- f tonum ;
@f map
"Numeric order: " print lmax ?
" " input</lang>
Klong
<lang k>list::[ 1.0 2.3 1.1 5.0 3 2.8 2.01 3.14159 77 ] |/list |/ [ 1.0 2.3 1.1 5.0 3 2.8 2.01 3.14159 66 ] |/ 1.0,2.3,1.1,5.0,3,2.8,2.01,3.14159,55</lang>
- Output:
77 66 55
Kotlin
Kotlin already has a 'max' function in its standard library so we use that: <lang scala>// version 1.0.5-2 fun main(args: Array<String>) {
print("Number of values to be input = ")
val n = readLine()!!.toInt()
val array = DoubleArray(n)
for (i in 0 until n) {
print("Value ${i + 1} = ")
array[i] = readLine()!!.toDouble()
}
println("\nThe greatest element is ${array.max()}")
}</lang> Example of use:
- Output:
Number of values to be input = 4 Value 1 = 70.5 Value 2 = 23.67 Value 3 = 150.2 Value 4 = 145 The greatest element is 150.2
Lambdatalk
<lang Scheme> 1) using the builtin primitive
{max 556 1 7344 4 7 52 22 55 88 122 55 99 1222 578} -> 7344
2) buidling a function
{def my-max
{def max-h
{lambda {:l :greatest}
{if {A.empty? :l}
then :greatest
else {max-h {A.rest :l}
{if {> {A.first :l} :greatest}
then {A.first :l}
else :greatest}}}}}
{lambda {:l}
{if {A.empty? :l} then empty else {max-h :l {A.first :l}}}}}
-> my-max
{my-max {A.new 556 1 7344 4 7 52 22 55 88 122 55 99 1222 578}} -> 7344 </lang>
Lasso
<lang Lasso>define greatest(a::array) => { return (#a->sort&)->last }
local(x = array(556,1,7344,4,7,52,22,55,88,122,55,99,1222,578)) greatest(#x)</lang>
- Output:
7344
LFE
Builtin. Using it from the LFE shell: <lang lisp>>(: lists max '[9 4 3 8 5]) 9</lang>
Liberty BASIC
<lang lb>aList$= "1 15 -5 6 39 1.5 14"
maxVal = val(word$(aList$, 1)) token$ = "?" while token$ <> ""
index = index + 1 token$ = word$(aList$, index) aVal = val(token$) if aVal > maxVal then maxVal = aVal
wend
print "maxVal = ";maxVal</lang>
Lingo
<lang lingo>l = [1,7,5] put max(l) -- 7</lang>
LiveCode
Max is built-in<lang livecode>put max(2,3,6,7,4,1)</lang> Result: 7
To be fair to the exercise, an alternative implementation could be<lang liveCode>function max2 lst
local maxNum
put item 1 of lst into maxNum
repeat with n = 1 to the number of items of lst
if item n of lst > maxNum then
put item n of lst into maxNum
end if
end repeat
return maxNum
end max2 on mouseUp
answer max2("1,2,5,6,7,4,3,2")
end mouseUp</lang>
Logo
If the template is, like SUM, the name of a procedure that is capable of accepting arbitrarily many inputs, it is more efficient to use APPLY instead of REDUCE. The latter is good for associative procedures that have been written to accept exactly two inputs: <lang logo>to max :a :b output ifelse :a > :b [:a] [:b] end
print reduce "max [...]</lang>
Alternatively, REDUCE can be used to write MAX as a procedure that accepts any number of inputs, as SUM does: <lang logo>to max [:inputs] 2 if emptyp :inputs ~
[(throw "error [not enough inputs to max])]
output reduce [ifelse ?1 > ?2 [?1] [?2]] :inputs end</lang> ==Logo==
<lang logo>to bigger :a :b
output ifelse [greater? :a :b] [:a] [:b]
end
to max :lst
output reduce "bigger :lst
end</lang>
Logtalk
<lang logtalk> max([X| Xs], Max) :-
max(Xs, X, Max).
max([], Max, Max). max([X| Xs], Aux, Max) :-
( X @> Aux ->
max(Xs, X, Max)
; max(Xs, Aux, Max)
).</lang>
Lua
<lang lua>-- Table to store values local values = {} -- Read in the first number from stdin local new_val = io.read"*n" -- Append all numbers passed in -- until there are no more numbers (io.read'*n' = nil) while new_val do
values[#values+1] = new_val new_val = io.read"*n"
end
-- Print the max print(math.max(unpack(values))) </lang>
M2000 Interpreter
<lang M2000 Interpreter> Module TestThis {
Print "Search a tuple type list (is an array also)"
A=(,)
For i=1 to Random(1,10)
Append A, (Random(1,100),)
Next
Print Len(A)
Print A
Print A#max()
Print "Search an array"
B=lambda->Random(1,100)
Rem Dim A(1 to Random(1,10))<<B()
Dim A(1 to Random(1,10))<<lambda->{=Random(1,100)}()
Print Len(A())
Print A()
Print A()#max()
\\ #max() skip non numeric values
Rem Print (1,"100",3)#max()=3
Print "Search an inventory list"
Inventory C
for i=1 to Random(1,10)
do
key=random(10000)
until not exist(c, key)
\\ we can put a number as string
if random(1,2)=1 then Append c, key:=B() else Append c, key:=str$(B())
Next
\\ if inventory item is string with a number work fine
Function MaxItem(a) {
k=each(a,2)
val=a(0!)
while k
\\ using stack of values
\\ over -equal to over 1 - copy value from 1 to top, means double the top value
\\ number - pop top value
\\ drop -equal to drop 1 : drop top value
Push a(k^!): Over : If Number>val then Read Val else drop
Rem If a(k^!)>Val Then Val=a(k^!)
end while
=val
}
Print Len(C)
Print C
Print MaxItem(C)
Print "Search a stack object"
\\ a stack object is the same as the stack of values
\\ which always is present
D=stack
I=0
J=Random(1,10)
\\ Stack stackobjext {}
\\ hide current stack and attach the D stack
Stack D {
Push B() : I++ : IF I>J Else Loop
}
\\ if stack item isn't numeric we get a run time error
Function MaxItemStack(a) {
Stack a {env$=envelope$()}
if replace$("N","", env$)<>"" then error "only numbers allowed"
k=each(a,2)
val=Stackitem(a,1)
while k
If Stackitem(k)>val then Val=stackitem(k)
end while
=val
}
Print Len(D)
Print D
Print MaxItemStack(D)
} TestThis </lang>
Maple
This is a built-in, polymorphic procedure in Maple. <lang Maple>> max( { 1, 2, Pi, exp(1) } ); # set
Pi
> max( [ 1, 2, Pi, exp(1) ] ); # list
Pi
> max( 1, 2, Pi, exp(1) ); # sequence
Pi
> max( Array( [ 1, 2, Pi, exp(1) ] ) ); # Array
Pi</lang>
For numeric data in (multi-dimensional) rtables, a particularly flexible and powerful method for finding the maximum (and many other things) is the use of "rtable_scanblock". The maximum of an Array is a built-in rtable_scanblock operation and can be found as follows. <lang Maple>> A := Array([1,2,4/5,3,11]): rtable_scanblock( A, [rtable_dims(A)], Maximum );
11</lang>
Mathematica / Wolfram Language
Input: <lang Mathematica>Max[1, 3, 3, 7] Max[Pi,E+2/5,17 Cos[6]/5,Sqrt[91/10]] Max[1,6,Infinity] Max[]</lang>
- Output:
7 17 Cos[6]/5 Infinity -Infinity
Note that Max returns minus infinity if supplied with no arguments; as it should: <lang Mathematica>Max[Max[],Max[a,b,c]] Max[Max[a],Max[b,c]] Max[Max[a,b],Max[c]] Max[Max[a,b,c],Max[]]</lang> should all give the same results, therefore max[] should give -Infinity. If it WOULD give 0 strange things can happen: <lang Mathematica>Max[Max[], Max[-4, -3]]</lang> WOULD give 0 instead of -3
MATLAB
<lang Matlab>function [maxValue] = findmax(setOfValues)
maxValue = max(setOfValues);</lang>
Maxima
<lang maxima>u : makelist(random(1000), 50)$
/* Three solutions */ lreduce(max, u);
apply(max, u);
lmax(u);</lang>
MAXScript
MAXScript has a built-in function called amax(), which will return the maximum of an array or the values supplied to it. The following custom function will return the maximum of the array supplied to it, or 'undefined' if an empty array is supplied. <lang MAXScript>fn MaxValue AnArray = ( if AnArray.count != 0 then ( local maxVal = 0 for i in AnArray do if i > maxVal then maxVal = i maxVal ) else undefined )</lang>
Metafont
The max macro (in the base set of macro for Metafont) accepts any number of arguments, and accepts both numerics (numbers), pairs (bidimensional vectors), and strings (not mixed).
<lang metafont>show max(4,5,20,1); show max((12,3), (10,10), (25,5)); show max("hello", "world", "Hello World");</lang>
min
<lang min>(
'bool ;does the list have any elements?
(-inf ('> 'pop 'nip if) reduce) ;do if so
({"empty seq" :error "Cannot find the maximum element of an empty sequence" :message} raise) ;do if not
if
) :seq-max</lang>
MiniScript
There is a list.max function in the listUtil module, but if you're working in an environment without this module or just want to write it yourself, you might do it as follows. <lang MiniScript>list.max = function()
if not self then return null
result = self[0]
for item in self
if item > result then result = item
end for
return result
end function
print [47, 11, 42, 102, 13].max</lang>
МК-61/52
<lang>П0 С/П x=0 07 ИП0 x<0 00 max БП 00</lang>
or
<lang>П0 ИП0 С/П - x<0 01 Вx П0 БП 01</lang>
Modula-3
Modula-3 provides a builtin MAX function, but it only works on two elements (or enumerations) but not arrays or sets.
We provide a generic Maximum implementation: <lang modula3>GENERIC INTERFACE Maximum(Elem);
EXCEPTION Empty;
PROCEDURE Max(READONLY a: ARRAY OF Elem.T): Elem.T RAISES {Empty};
END Maximum.</lang>
<lang modula3>GENERIC MODULE Maximum(Elem);
PROCEDURE Max(READONLY arr: ARRAY OF Elem.T): Elem.T RAISES {Empty} =
VAR max := FIRST(Elem.T);
BEGIN
IF NUMBER(arr) = 0 THEN
RAISE Empty;
END;
FOR i := FIRST(arr) TO LAST(arr) DO
IF arr[i] > max THEN
max := arr[i];
END;
END;
RETURN max;
END Max;
BEGIN END Maximum.</lang>
Elem can be instantiated to any type (any type that can be compared with the '>' function). For convenience Modula-3 provides interfaces/modules for the built in types, like Integer, Real, LongReal, etc, which contain type definitions as well as properties specific to the type.
To make a generic interface/module for a specific type, you must instantiate it: <lang modula3>INTERFACE RealMax = Maximum(Real) END RealMax.</lang> <lang modula3>MODULE RealMax = Maximum(Real) END RealMax.</lang>
Now we can import RealMax into our source and use the Max function:
<lang modula3>MODULE Main;
IMPORT RealMax, IO, Fmt;
VAR realarr := ARRAY [1..5] OF REAL {1.1, 1.0, 0.0, 2.4, 3.3};
BEGIN
IO.Put(Fmt.Real(RealMax.Max(realarr)) & "\n");
END Main.</lang>
MontiLang
MontiLang has a builtin statement MAX which finds the maximum of the top two items on the stack. By looping through an array and pushing to the stack, the largest item in an array can be found.
<lang MontiLang>2 5 3 12 9 9 56 2 ARR
LEN VAR l . 0 VAR i . FOR l
GET i SWAP i 1 + VAR i .
ENDFOR . STKLEN 1 - VAR st . FOR st
MAX
ENDFOR PRINT</lang>
Another way to do it.
<lang MontiLang>2 5 3 12 9 9 56 2 ARR print LEN VAR l . 0 VAR i . 0 FOR l
swap GET i rot max i 1 + VAR i .
ENDFOR |Greatest number in the list: | out . print |Press ENTER to exit | input clear</lang>
MUMPS
<lang MUMPS> MV(A,U)
;A is a list of values separated by the string U NEW MAX,T,I FOR I=1:1 SET T=$PIECE(A,U,I) QUIT:T="" S MAX=$SELECT(($DATA(MAX)=0):T,(MAX<T):T,(MAX>=T):MAX) QUIT MAX
</lang> Usage:
USER>SET V="," USER>SET B="-1,-1000,1000,2.3E5,8A,""A"",F" USER>W $$MV^ROSETTA(B,V) 2.3E5
Nanoquery
<lang Nanoquery>def max(list) if len(list) = 0 return null end
largest = list[0] for val in list if val > largest largest = val end end return largest end</lang>
Neko
<lang ActionScript>/**
greatest element from a list (Neko Array) Tectonics: nekoc greatest-element.neko neko greatest-element
- /
var greatest = function(list) {
var max, element; var pos = 1;
if $asize(list) > 0 max = list[0];
while pos < $asize(list) {
element = list[pos];
if max < element max = element;
pos += 1;
}
return max;
}
$print(greatest($array(5, 1, 3, 5)), "\n"); $print(greatest($array("abc", "123", "zyx", "def")), "\n");</lang>
- Output:
prompt$ nekoc greatest-element.neko prompt$ neko ./greatest-element.n 5 zyx
Nemerle
<lang Nemerle>using System; using Nemerle.Collections; using System.Linq; using System.Console;
module SeqMax {
SeqMax[T, U] (this seq : T) : U
where T : Seq[U]
where U : IComparable
{
$[s | s in seq].Fold(seq.First(), (x, y) => {if (x.CompareTo(y) > 0) x else y})
}
Main() : void
{
def numbers = [1, 12, 3, -5, 6, 23];
def letters = ['s', 'p', 'a', 'm'];
// using SeqMax() method (as task says to "create a function")
WriteLine($"numbers.SeqMax() = $(numbers.SeqMax())");
WriteLine($"letters.SeqMax() = $(letters.SeqMax())");
// using the already available Max() method
WriteLine($"numbers.Max() = $(numbers.Max())");
WriteLine($"letters.Max() = $(letters.Max())")
}
}</lang>
- Output:
numbers.SeqMax() = 23 letters.SeqMax() = s numbers.Max() = 23 letters.Max() = s
NetRexx
<lang NetRexx>/* NetRexx */
options replace format comments java crossref savelog symbols binary
rn = Random() maxElmts = 100 dlist = double[maxElmts] rlist = Rexx[maxElmts] loop r_ = 0 to maxElmts - 1
nr = rn.nextGaussian * 100.0 dlist[r_] = nr rlist[r_] = Rexx(nr) end r_
say 'Max double:' Rexx(getMax(dlist)).format(4, 9) say 'Max Rexx:' getMax(rlist).format(4, 9)
return
method getMax(dlist = double[]) public static binary returns double
dmax = Double.MIN_VALUE loop n_ = 0 to dlist.length - 1 if dlist[n_] > dmax then dmax = dlist[n_] end n_ return dmax
method getMax(dlist = Rexx[]) public static binary returns Rexx
dmax = Rexx(Double.MIN_VALUE) loop n_ = 0 to dlist.length - 1 dmax = dlist[n_].max(dmax) end n_ return dmax
</lang>
- Output:
Max double: 274.457568703 Max Rexx: 274.457568703
NewLISP
<lang NewLISP>(max 1 2 3 5 2 3 4)</lang>
<lang NEWLISP>(apply max '(1 2 3 5 2 3 4)) ; apply to list
- Added by Nehal-Singhal 2018-05-29</lang>
Nial
The behavior of multi-dimensional arrays is like J
<lang nial>max 1 2 3 4 =4</lang>
Nim
<lang Nim>echo max([2,3,4,5,6,1])</lang>
- Output:
6
Oberon-2
<lang oberon2> MODULE GreatestElement1; IMPORT
ADT:ArrayList, Object:Boxed, Out;
VAR
a: ArrayList.ArrayList(Boxed.LongInt);
max: Boxed.LongInt;
PROCEDURE Max(al: ArrayList.ArrayList(Boxed.LongInt)): Boxed.LongInt;
VAR
i: LONGINT;
item, max: Boxed.LongInt;
BEGIN
max := NEW(Boxed.LongInt,MIN(LONGINT));
i := 0;
WHILE (i < al.size) DO
item := al.Get(i);
IF item.value > max.value THEN max := item END;
INC(i)
END;
RETURN max
END Max;
BEGIN
a := NEW(ArrayList.ArrayList(Boxed.LongInt),5);
a.Append(NEW(Boxed.LongInt,10));
a.Append(NEW(Boxed.LongInt,32));
a.Append(NEW(Boxed.LongInt,4));
a.Append(NEW(Boxed.LongInt,43));
a.Append(NEW(Boxed.LongInt,9));
max := Max(a);
Out.String("Max: ");Out.LongInt(max.value,4);Out.Ln
END GreatestElement1. </lang>
Simple version <lang oberon2> MODULE GreatestElement2; IMPORT
Out;
VAR
a: ARRAY 10 OF LONGINT;
PROCEDURE Max(a: ARRAY OF LONGINT): LONGINT;
VAR
i, max: LONGINT;
BEGIN
max := MIN(LONGINT);
FOR i := 0 TO LEN(a) - 1 DO
IF a[i] > max THEN max := a[i] END;
END;
RETURN max
END Max;
BEGIN
a[0] := 10;
a[1] := 32;
a[2] := 4;
a[3] := 43;
a[4] := 9;
Out.String("Max: ");Out.LongInt(Max(a),4);Out.Ln
END GreatestElement2. </lang>
- Output:
(in both programs)
Max: 43
Objeck
The language has a "Max" method for vectors. <lang objeck> values := IntVector->New([4, 1, 42, 5]); values->Max()->PrintLine(); </lang>
Objective-C
This code "extends" (through Objective-C categories) the NSArray adding the method
maximumValue; this one iterates over the objects of the collection
calling the method compare, if it exists for the object of the
collection. Since normally comparing makes sense between numbers, the code
also check if the objects being compared are of "kind" NSNumber. If one eliminates
this check (substituting it maybe with one that checks if the two object are of
the same "kind"), the code is able to get a maximum value for any objects for
which make sense a compare method (e.g. strings), that must be implemented.
If there's no a known way of comparing two objects of the collection (or if the objects are not "NSNumber"), the the method return nil (the void object).
<lang objc>#import <Foundation/Foundation.h>
@interface NSArray (WithMaximum) - (id)maximumValue; @end
@implementation NSArray (WithMaximum) - (id)maximumValue {
if ( [self count] == 0 ) return nil;
id maybeMax = self[0];
for ( id el in self ) {
if ( [maybeMax respondsToSelector: @selector(compare:)] &&
[el respondsToSelector: @selector(compare:)] && [el isKindOfClass: [NSNumber class]] && [maybeMax isKindOfClass: [NSNumber class]] ) {
if ( [maybeMax compare: el] == NSOrderedAscending )
maybeMax = el;
} else { return nil; }
}
return maybeMax;
} @end</lang>
This example mixes integers with a double value, just to show that everything is fine until they are NSNumber.
<lang objc>int main() {
@autoreleasepool {
NSArray *collection = @[@1, @2, @10, @5, @10.5];
NSLog(@"%@", [collection maximumValue]);
}
return 0;
}</lang>
OCaml
<lang ocaml>let my_max = function
[] -> invalid_arg "empty list" | x::xs -> List.fold_left max x xs</lang>
# my_max [4;3;5;9;2;3] ;; - : int = 9
Octave
Octave's max accepts a vector (and can return also the index of the maximum value in the vector)
<lang octave>m = max( [1,2,3,20,10,9,8] ); % m = 20 [m, im] = max( [1,2,3,20,10,9,8] ); % im = 4</lang>
Oforth
<lang Oforth>[1, 2.3, 5.6, 1, 3, 4 ] reduce(#max)</lang>
Ol
Basics: <lang scheme>
- builtin function
(max 1 2 3 4 5) ; 5
(define x '(1 2 3 4 5))
- using to numbers list
(apply max x) ; 5
- using list reducing
(fold max (car x) x) ; 5
- manual lambda-comparator
(print (fold (lambda (a b)
(if (less? a b) b a)) (car x) x)) ; 5
</lang>
ooRexx
version
<lang ooRexx> -- routine that will work with any ordered collection or sets and bags containing numbers.
- routine listMax
use arg list items list~makearray -- since we're dealing with different collection types, reduce to an array if items~isEmpty then return .nil -- return a failure indicator. could also raise an error, if desired largest = items[1]
-- note, this method does call max one extra time. This could also use the
-- do i = 2 to items~size to avoid this
do item over items
largest = max(item, largest)
end
return largest
</lang>
version 2 works with any strings
<lang>/* REXX ***************************************************************
- 30.07.2013 Walter Pachl as for REXX
- /
s=.list~of('Walter','lives','in','Vienna') say listMax(s) -- routine that will work with any ordered collection or sets and bags.
- routine listMax
use arg list
items=list~makearray -- since we're dealing with different collection types, reduce to an array
if items~isEmpty then return .nil -- return a failure indicator. could also raise an error, if desired
largest = items[1]
-- note, this method uses one extra comparison. It could use
-- do i = 2 to items~size to avoid this
do item over items
If item>>largest Then
largest = item
end
return largest</lang>
OxygenBasic
<lang> 'Works on any list with element types which support '>' comparisons
macro max any(R, A, N, i)
================
scope
indexbase 1
int i
R=A(1)
for i=2 to N
if A(i)>R
R=A(i)
endif
next
end scope
end macro
'DEMO
=
redim double d(100) d={ 1.1, 1.2, 5.5, -0.1, -12.0 } double m=max(d,5) print "greatest element of d(): " m '5.5 </lang>
Oz
<lang oz>declare
fun {Maximum X|Xr} %% pattern-match on argument to make sure the list is not empty
{FoldL Xr Value.max X} %% fold the binary function Value.max over the list
end
in
{Show {Maximum [1 2 3 4 3]}}</lang>
PARI/GP
<lang parigp>vecmax(v)</lang>
Pascal
See Delphi
or try this, for it shows the according position <lang pascal>program GElemLIst; {$IFNDEF FPC}
{$Apptype Console}
{$else}
{$Mode Delphi}
{$ENDIF}
uses
sysutils;
const
MaxCnt = 1000000;
type
tMaxIntPos= record
mpMax,
mpPos : integer;
end;
tMaxfltPos= record
mpMax : double;
mpPos : integer;
end;
function FindMaxInt(const ia: array of integer):tMaxIntPos;
//delivers the highest Element and position of integer array
var
i : NativeInt; tmp,max,ps: integer;
Begin
max := -MaxInt-1;
ps := -1;
//i = index of last Element
i := length(ia)-1;
IF i>=0 then Begin
max := ia[i];
ps := i;
dec(i);
while i> 0 do begin
tmp := ia[i];
IF max< tmp then begin
max := tmp;
ps := i;
end;
dec(i);
end;
end;
result.mpMax := Max;
result.mpPos := ps;
end;
function FindMaxflt(const ia: array of double):tMaxfltPos; //delivers the highest Element and position of double array var
i, ps: NativeInt; max : double; tmp : ^double;//for 32-bit version runs faster
Begin
max := -MaxInt-1;
ps := -1;
//i = index of last Element
i := length(ia)-1;
IF i>=0 then Begin
max := ia[i];
ps := i;
dec(i);
tmp := @ia[i];
while i> 0 do begin
IF tmp^>max then begin
max := tmp^;
ps := i;
end;
dec(i);
dec(tmp);
end;
end;
result.mpMax := Max;
result.mpPos := ps;
end;
var
IntArr : array of integer; fltArr : array of double; ErgInt : tMaxINtPos; ErgFlt : tMaxfltPos; i: NativeInt;
begin
randomize; setlength(fltArr,MaxCnt); //filled with 0 setlength(IntArr,MaxCnt); //filled with 0.0 For i := High(fltArr) downto 0 do fltArr[i] := MaxCnt*random(); For i := High(IntArr) downto 0 do IntArr[i] := round(fltArr[i]);
ErgInt := FindMaxInt(IntArr);
writeln('FindMaxInt ',ErgInt.mpMax,' @ ',ErgInt.mpPos);
Ergflt := FindMaxflt(fltArr);
writeln('FindMaxFlt ',Ergflt.mpMax:0:4,' @ ',Ergflt.mpPos);
end.</lang> Out, because of the searchdirection Position of FindMaxFlt is below FindMaxInt
FindMaxInt 999999 @ 691620 FindMaxFlt 999999.0265 @ 14824
Perl
<lang perl>sub max {
my $max = shift;
for (@_) { $max = $_ if $_ > $max }
return $max;
}</lang>
It is already implemented in the module List::Util's max() function: <lang perl>use List::Util qw(max);
max(@values);</lang>
Phix
with javascript_semantics ?max({1,1234,62,234,12,34,6}) ?max({"ant", "antelope", "dog", "cat", "cow", "wolf", "wolverine", "aardvark"})
- Output:
1234 "wolverine"
Phixmonti
<lang Phixmonti>"1" "1234" "62" "234" "12" "34" "6" stklen tolist dup "Alphabetic order: " print max print nl
len for
var i i get tonum i set
endfor "Numeric order: " print max print</lang>
With syntactic sugar
<lang Phixmonti>include ..\Utilitys.pmt
( "1" "1234" "62" "234" "12" "34" "6" )
dup "Alphabetic order: " print max print nl
def f
tonum
enddef
getid f map
dup "Numeric order: " print max print </lang>
PHP
The built-in PHP function max() already does this. <lang php>max($values)</lang>
PicoLisp
<lang PicoLisp>: (max 2 4 1 3) # Return the maximal argument -> 4
- (apply max (2 4 1 3)) # Apply to a list
-> 4
- (maxi abs (2 -4 -1 3)) # Maximum according to given function
-> -4</lang>
PL/I
<lang pli> maximum = A(lbound(A,1)); do i = lbound(A,1)+1 to hbound(A,1);
if maximum < A(i) then maximum = A(i);
end; </lang>
PostScript
Ghostscript has a max built-in:
<lang postscript>/findmax {
dup 0 get exch % put the first element underneath the array
{max} forall % replace it by the respective larger value if necessary
} def</lang>
If not using Ghostscript this gets a bit longer:
<lang postscript>/findmax {
dup 0 get exch % put the first element underneath the array
{
dup % duplicate the current item
2 index % duplicate the current maximum value
gt % if the current item is larger
{exch} if % swap the two items so the previous maximum is now the top of the stack
pop % remove it
} forall
} def</lang>
<lang postscript> [1 2 3 4 5 4 3 2 1] uncons exch {max} fold </lang>
PowerBASIC
<lang powerbasic>FUNCTION PBMAIN()
DIM x AS LONG, y AS LONG, z AS LONG RANDOMIZE TIMER
FOR x = 1 TO 10
y = INT(RND * 10000)
z = MAX(y, z)
NEXT
? STR$(z) & " was the highest value"
END FUNCTION</lang>
- Output:
8104 was the highest value
PowerShell
The Measure-Object cmdlet in PowerShell already has this capability:
<lang powershell>function Get-Maximum ($a) {
return ($a | Measure-Object -Maximum).Maximum
}</lang>
Prolog
SWI-Prolog already knows max_list. <lang Prolog> ?- max_list([1, 2, 10, 3, 0, 7, 9, 5], M). M = 10.</lang>
can be implemented like this:
<lang Prolog>max_list(L, V) :- select(V, L, R), \+((member(X, R), X > V)). </lang>
PureBasic
<lang PureBasic>Procedure.f Max (Array a.f(1))
Protected last, i, ret.f
ret = a(0)
last = ArraySize(a())
For i = 1 To last
If ret < a(i)
ret = a(i)
EndIf
Next
ProcedureReturn ret
EndProcedure</lang>
PureBasic: another solution
<lang purebasic>Procedure.f maxelement(List tl.f())
ForEach tl() : mx.f=mx*Bool(mx>=tl())+tl()*Bool(mx<tl()) : Next ProcedureReturn mx
EndProcedure
NewList testlist.f() : OpenConsole() For i=0 To 99 : AddElement(testlist()) : testlist()=Sqr(Random(1000)) : Next Print("Greatest element = "+StrF(maxelement(testlist()),8)) : Input()</lang>
- Output:
Greatest element = 31.59113884
Python
The built-in Python function max() already does this. <lang python>max(values)</lang>
Of course this assumes we have a list or tuple (or other sequence like object). (One can even find the max() or min() character of a string since that's treated as a sequence of characters and there are "less than" and "greater than" operations (object methods) associate with those characters).
If we truly were receiving a stream of data then in Python, such streams are usually iterable, meaning they have a way of generating one item at a time from the stream.
max(), (and min()), can take iterables and a key argument which takes a function that can transform each item into a type that we can compare, for example, if the stream were returning string representations of integers, one to a line, you could do <lang python>>>> floatstrings = ['1\n', ' 2.3\n', '4.5e-1\n', '0.01e4\n', '-1.2'] >>> max(floatstrings, key = float) '0.01e4\n' >>></lang> Normally we would want the converted form as the maximum and we could just as easily write: <lang python>>>> max(float(x) for x in floatstrings) 100.0 >>></lang> Or you can write your own functional version, of the maximum function, using reduce and lambda <lang python>>>> mylist = [47, 11, 42, 102, 13] >>> reduce(lambda a,b: a if (a > b) else b, mylist) 102</lang>
Q
<lang Q>q)l:2 9 3 8 4 7 q)max l 9</lang>
Quackery
<lang Quackery>[ behead swap witheach max ] is [max] ( [ --> n )</lang>
R
<lang R>v <- c(1, 2, 100, 50, 0) print(max(v)) # 100</lang>
Racket
The "max" function it built in and takes an arbitrary amount of arguments. <lang racket>(max 12 9 8 17 1)</lang>
- Output:
17
To use with a list, there is apply: <lang racket>(apply max '(12 9 8 17 1))</lang>
However, if you want to write the function yourself: <lang racket> (define (my-max l)
(define (max-h l greatest)
(cond [(empty? l) greatest]
[(> (first l) greatest) (max-h (rest l) (first l))]
[else (max-h (rest l) greatest)]))
(if (empty? l) empty (max-h l (first l))))
</lang>
or with a "for" loop: <lang racket> (define (my-max l)
(for/fold ([max #f]) ([x l]) (if (and max (> max x)) max x)))
</lang>
Raku
(formerly Perl 6) The built-in function works with any type that defines ordering. <lang perl6>say max 10, 4, 5, -2, 11; say max <zero one two three four five six seven eight nine>;
- Even when the values and number of values aren't known until runtime
my @list = flat(0..9,'A'..'H').roll((^60).pick).rotor(4,:partial)».join.words; say @list, ': ', max @list; </lang>
- Sample output:
11 zero [6808 013C 6D5B 4219 29G9 DC13 CA4F 55F3 AA06 0AGF DAB0 2]: DC13
RapidQ
<lang vb>functioni FindMax(...) as double
dim x as integer
for x = 1 to ParamValCount
IF ParamVal(x) > Result THEN Result = ParamVal(x)
next
End functioni
Print FindMax(50, 20, 65, 20, 105) </lang>
Rascal
Rascal has a built-in function that gives the greatest element of a list <lang rascal> rascal>import List; ok
rascal>max([1,2,3,4]); int: 4 </lang>
Raven
<lang Raven>[ 1 2 3 4 ] max "%d\n" print</lang>
- Output:
4
Randomly generated list size and elements <lang Raven>100 choose as $cnt [ ] as $lst 0 $cnt 1 range each drop 100 choose $lst push $lst print $lst max "max value: %d\n" print</lang>
REBOL
<lang REBOL>REBOL [
Title: "Maximum Value" URL: http://rosettacode.org/wiki/Maximum_Value
]
max: func [ "Find maximum value in a list." values [series!] "List of values." ] [ first maximum-of values ]
print ["Max of" mold d: [5 4 3 2 1] "is" max d] print ["Max of" mold d: [-5 -4 -3 -2 -1] "is" max d]</lang>
- Output:
Max of [5 4 3 2 1] is 5 Max of [-5 -4 -3 -2 -1] is -1
Red
<lang Red>Red [] list: [1 2 3 5 4] print last sort list </lang>
REXX
The numbers in the list may be any valid REXX number (integer, negative, floating point, etc.)
using a list
<lang rexx>/*REXX program finds the greatest element in a list (of the first 25 reversed primes).*/ $ = reverse(2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97) say 'list of numbers = ' $ /*show the original list of numbers. */ big=word($, 1) /*choose an initial biggest number. */
- = words($); do j=2 to # /*traipse through the list, find max. */
big=max(big, word($, j) ) /*use the MAX BIF to find the biggie.*/
end /*j*/
say /*stick a fork in it, we're all done. */ say 'the biggest value in a list of ' # " numbers is: " big</lang>
- output when using the default (internal) input:
list of numbers = 79 98 38 97 37 17 76 16 95 35 74 34 14 73 13 92 32 91 71 31 11 7 5 3 2 the biggest value in a list of 25 numbers is: 98
using an array
<lang rexx>/*REXX program finds the greatest element in a list (of the first 25 reversed primes).*/ @.=; @.1 = 2; @.2 = 3; @.3 = 5; @.4 = 7; @.5 =11; @.6 =31; @.7 =71
@.8 =91; @.9 =32; @.10=92; @.11=13; @.12=73; @.13=14; @.14=34
@.15=74; @.16=35; @.17=95; @.18=16; @.19=76; @.20=17; @.21=37
@.22=97; @.23=38; @.24=98; @.25=79
big=@.1 /*choose an initial biggest number. */
do #=2 while @.#\== /*traipse through whole array of nums. */
big = max(big, @.#) /*use a BIF to find the biggest number.*/
end /*#*/
/*stick a fork in it, we're all done. */
say 'the biggest value in an array of ' #-1 " elements is: " big</lang>
- output when using the default (internal) input:
the biggest value in an array of 25 elements is: 98
using a list from the terminal
<lang rexx>/*REXX program finds the greatest element in a list of numbers entered at the terminal*/ say '────────────────── Please enter a list of numbers (separated by blanks or commas):' parse pull $; #=words($) /*get a list of numbers from terminal. */ $=translate($, , ',') /*change all commas (,) to blanks. */ big=word($,1); do j=2 to # /*traipse through the list of numbers. */
big=max(big, word($,j)) /*use a BIF for finding the max number.*/
end /*j*/
say /*stick a fork in it, we're all done. */ say '────────────────── The biggest value in the list of ' # " elements is: " big</lang> Programming note: the max BIF normalizes the number returned (eliding the leading superfluous zeroes).
If this is undesirable, then the do loop (shown above) can be replaced with: <lang rexx>···; do j=2 to #; _=word($,j)
if _>big then big=_
end /*j*/</lang>
- output when using the input from the terminal via a user prompt:
────────────────── Please enter a list of numbers (separated by blanks or commas): -12 -3 0 1.1 1e2 99.2 00245 ◄■■■■■■■■■■ user input ────────────────── The biggest value in the list of 7 elements is: 245
list of any strings
<lang rexx>/* REXX ***************************************************************
- If the list contains any character strings, the following will work
- Note the use of >> (instead of >) to avoid numeric comparison
- Note that max() overrides the builtin function MAX
- 30.07.2013 Walter Pachl
- /
list='Walter Pachl living in Vienna' Say max(list) list='8 33 -12' Say max(list) Exit max: Procedure Parse Arg l max=word(l,1) Do i=2 To words(l)
If word(l,i)>>max Then max=word(l,i) End
Return max</lang>
- output when using an ASCII system:
living 8
- output when using an EBCDIC system:
Walter 8
output when using a list which is: 12 111111 1 (lexigraphically 12 is greater than 111111)
12
Ring
<lang ring>aList = [1,2,4,5,10,6,7,8,9] see max(aList)</lang>
- Output:
10
Ruby
max is a method of all Enumerables <lang ruby>values.max</lang>
Run BASIC
<lang Runbasic>list$= "1 12 -55 46 41 3.66 19" while word$(list$,i+1," ") <> ""
mx = max(mx,val(word$(list$,i+1," "))) i = i + 1
wend print mx</lang>
Rust
This is built in functionality for everything that can be iterated over. It returns an Option<T>, meaning Some(e) if there are elements in the iterator and None if it is empty. <lang rust>fn main() {
let nums = [1,2,39,34,20];
println!("{:?}", nums.iter().max());
println!("{}", nums.iter().max().unwrap());
}</lang>
- Output:
Some(39) 39
S-lang
Starting w/an array, this is trivial: <lang S-lang>variable a = [5, -2, 0, 4, 666, 7]; print(max(a));</lang>
output: 666
If a is a list instead of an array, then: <lang S-lang>a = {5, -2, 0, 4, 666, 7}; print(max(list_to_array(a)));</lang>
Scala
<lang Scala>def noSweat(list: Int*) = list.max // Test assert(noSweat(1, 3, 12, 7) == 12)</lang>
Scheme
The built-in Scheme function max takes the max of all its arguments. <lang scheme>(max 1 2 3 4) (apply max values) ; find max of a list</lang>
Seed7
<lang seed7>$ include "seed7_05.s7i";
const func integer: max (in array integer: values) is func
result
var integer: max is 0;
local
var integer: index is 0;
begin
max := values[1];
for index range 2 to length(values) do
if values[index] > max then
max := values[index];
end if;
end for;
end func;
const proc: main is func
begin writeln(max([] (1, 2, 6, 4, 3))); end func;</lang>
- Output:
6
Self
Using reduceWith: it is very simple to find the maximum value among a collection.
<lang self>(1 & 2 & 3 & 4 & 20 & 10 & 9 & 8) asVector reduceWith: [:a :b | a max: b] "returns 20"</lang>
Or, since it's "built-in", you can simply do:
<lang self>(1 & 2 & 3 & 4 & 20 & 10 & 9 & 8) asVector max. "returns 20"</lang>
SenseTalk
<lang sensetalk>put the max of (1, 5, 666, -1000, 3) put the highest value of [88,-2,6,55,103,0]</lang> Output: <lang sensetalk>666 103</lang>
Sidef
max method returns the greatest element in a list. It works only if the array's elements have the same type (e.g.: strings, numbers). <lang ruby>values.max;</lang>
Slate
<lang slate>#(1 2 3 4 20 10 9 8) reduce: [| :a :b | a max: b]</lang>
Smalltalk
Using fold it is very simple to find the maximum value among a collection.
<lang smalltalk>#(1 2 3 4 20 10 9 8) fold: [:a :b | a max: b] "returns 20"</lang>
Or, since it's "built-in", you can simply do:
<lang smalltalk>#(1 2 3 4 20 10 9 8) max. "returns 20"</lang>
using #inject:into: <lang smalltalk> | list | list := #(1 2 3 4 20 10 9 8). list inject: (list at: 1) into: [ :number :each |
number max: each ]
</lang>
SNOBOL4
<lang snobol4>while a = trim(input) :f(stop)
max = gt(a,max) a :(while)
stop output = max end</lang>
Standard ML
Comparisons are specific for each type. Here is a max function for a list of ints: <lang sml>fun max_of_ints [] = raise Empty
| max_of_ints (x::xs) = foldl Int.max x xs</lang>
- max_of_ints [4,3,5,9,2,3]; val it = 9 : int
Stata
Use the summarize command to compute the maximum value of a variable:
<lang stata>qui sum x di r(max)</lang>
Mata has also several functions to compute minimum or maximum of a vactor or matrix:
<lang stata>a = 1,5,3,4,2,7,9,8 max(a)</lang>
Swift
<lang swift>if let x = [4,3,5,9,2,3].maxElement() {
print(x) // prints 9
}</lang>
<lang swift>let x = maxElement([4,3,5,9,2,3]) println(x) // prints 9</lang>
Tailspin
Simplest is to use the built-in collector <lang tailspin> [1, 5, 20, 3, 9, 7] ... -> ..=Max&{by: :(), select: :()} -> !OUT::write // outputs 20
// This is how the Max-collector is implemented in the standard library: processor Max&{by:, select:}
@:[];
sink accumulate
<?($@Max <=[]>)
| ?($(by) <$@Max.max..>)> @Max: {max: $(by), result: $(select)};
end accumulate
source result
$@Max.result !
end result
end Max </lang> But here is how to find the max more manually/programmatically, it is pretty easy as well <lang tailspin> templates max
@: $(1); $(2..last)... -> # $@! when <$@..> do @: $;
end max
[1, 5, 20, 3, 9, 7] -> max -> !OUT::write // outputs 20 </lang> Can also be written as an inline templates <lang tailspin> [1, 5, 20, 3, 9, 7] -> \(@: $(1); $(2..last)... -> # $@ ! when <$@..> do @: $;\) -> !OUT::write // outputs 20 </lang> Or we can do just the matching in an inline templates referencing the outer state <lang tailspin> templates max
@: $(1); $(2..last)... -> \(<$@max..> @max: $;\) -> !VOID $@!
end max
[1, 5, 20, 3, 9, 7] -> max -> !OUT::write // outputs 20 </lang>
Tcl
Use the {*} expansion operator to substitute the list value with its constituent elements
<lang tcl>package require Tcl 8.5
set values {4 3 2 7 8 9}
- tcl::mathfunc::max {*}$values ;# ==> 9</lang>
TI-83 BASIC
The builtin max function can be applied to lists. max({1, 3, 2.
TI-89 BASIC
The builtin max function can be applied to lists. max({1, 3, 2}) = 3.
Transd
<lang scheme>#lang transd
MainModule: {
_start: (λ
(textout (max 9 6 2 11 3 4) " ")
(with v [1, 45, 7, 274, -2, 34]
(textout (max-element v) " ")
(textout (max-element-idx v))
))
}</lang>
- Output:
11 274 3
Trith
<lang trith>[1 -2 3.1415 0 42 7] [max] foldl1</lang>
TUSCRIPT
<lang tuscript> $$ MODE TUSCRIPT LOOP n,list="2'4'0'3'1'2'-12" IF (n==1) greatest=VALUE(list) IF (list>greatest) greatest=VALUE(list) ENDLOOP PRINT greatest </lang>
- Output:
4
uBasic/4tH
Since uBasic/4tH has a stack, it's only logical to use it. <lang>Push 13, 0, -6, 2, 37, -10, 12 ' Push values on the stack Print "Maximum value = " ; FUNC(_FNmax(7)) End ' We pushed seven values
_FNmax Param(1)
Local(3)
d@ = -(2^31) ' Set maximum to a tiny value
For b@ = 1 To a@ ' Get all values from the stack c@ = Pop() If c@ > d@ THEN d@ = c@ ' Change maximum if required Next
Return (d@) ' Return the maximum</lang>
UNIX Shell
<lang bash>max() {
local m=$1 shift while [ $# -gt 0 ] do [ "$m" -lt "$1" ] && m=$1 shift done echo "$m"
}
max 10 9 11 57 1 12</lang>
<lang bash>max() {
m=$1 # Bourne Shell has no local command. shift while [ $# -gt 0 ] do [ "$m" -lt "$1" ] && m=$1 shift done echo "$m"
}</lang>
Ursa
The max function:
<lang ursa>def max (int<> list)
decl int max i
set max list<0>
for (set i 1) (< i (- (size list) 1)) (inc i) if (> list max) set max list end if end for
return max end max</lang>
In use: (assuming the function is in the file max.u)
cygnus/x ursa v0.75 (default, release 0) [Oracle Corporation JVM 1.8.0_51 on Mac OS X 10.10.5 x86_64] > import "max.u" > decl int<> list > append 5 1 7 3 9 2 list > out (max list) endl console 9 > _
Ursala
The built-in $^ operator takes a binary predicate of any type to a
function extracting the maximum value from a non-empty list of that type. In this
case it is used with fleq, the partial order relation on floating point
numbers.
<lang Ursala>#import flo
- cast %e
example = fleq$^ <-1.,-2.,0.,5.,4.,6.,1.,-5.></lang>
- Output:
6.000000e+00
V
Assuming it is a list of positive numbers <lang v>[4 3 2 7 8 9] 0 [max] fold =9</lang>
If it is not <lang v>[4 3 2 7 8 9] dup first [max] fold</lang>
=9
VBA
<lang vb>Option Explicit
Sub Main() Dim a
a = Array(1, 15, 19, 25, 13, 0, -125, 9) Debug.Print Max_VBA(a)
End Sub
Function Max_VBA(Arr As Variant) As Long Dim i As Long, temp As Long
temp = Arr(LBound(Arr))
For i = LBound(Arr) + 1 To UBound(Arr)
If Arr(i) > temp Then temp = Arr(i)
Next i
Max_VBA = temp
End Function</lang>
- Output:
25
VBScript
<lang vb> Function greatest_element(arr) tmp_num = 0 For i = 0 To UBound(arr) If i = 0 Then tmp_num = arr(i) ElseIf arr(i) > tmp_num Then tmp_num = arr(i) End If Next greatest_element = tmp_num End Function
WScript.Echo greatest_element(Array(1,2,3,44,5,6,8)) </lang>
- Output:
44
Vim Script
for numbers (not floats): <lang vim>max([1, 3, 2])</lang> result: 3
for strings (with configurable ignore-case): <lang vim>function! Max(list, ...)
" {list} list of strings
" {a:1} 'i': ignore case, 'I': match case, otherwise use 'ignorecase' option
if empty(a:list)
return 0
endif
let gt_op = a:0>=1 ? get({'i': '>?', 'I': '>#'}, a:1, '>') : '>'
let cmp_expr = printf('a:list[idx] %s maxval', gt_op)
let maxval = a:list[0]
let len = len(a:list)
let idx = 1
while idx < len
if eval(cmp_expr) let maxval = a:list[idx] endif let idx += 1
endwhile return maxval
endfunction</lang>
Visual Basic
<lang vb>Public Function ListMax(anArray())
'return the greatest element in array anArray
'use LBound and UBound to find its length
n0 = LBound(anArray)
n = UBound(anArray)
theMax = anArray(n0)
For i = (n0 + 1) To n
If anArray(i) > theMax Then theMax = anArray(i)
Next
ListMax = theMax
End Function
Public Sub ListMaxTest()
Dim b() 'test function ListMax 'fill array b with some numbers: b = Array(5992424433449#, 4534344439984#, 551344678, 99800000#) 'print the greatest element Debug.Print "Greatest element is"; ListMax(b())
End Sub</lang>
Result:
ListMaxTest Greatest element is 5992424433449
Wart
Wart defines max in terms of the more general best.
<lang python>def (best f seq)
if seq
ret winner car.seq
each elem cdr.seq
if (f elem winner)
winner <- elem
def (max ... args)
(best (>) args)</lang>
(>) is > while suppressing infix expansion.
WDTE
<lang wdte>let s => import 'stream'; let a => import 'arrays';
let max list =>
a.stream list -> s.extent 1 > -> at 0 ;</lang>
extent is a standard library function that returns a sorted list of the elements of a stream that fit the given function best, so > results in the maximum element.
Wortel
The @maxl returns the maximum value of a list:
<lang wortel>@maxl [1 6 4 6 4 8 6 3] ; returns 8</lang>
Wren
<lang ecmascript>var max = Fn.new { |a| a.reduce { |m, x| (x > m) ? x : m } }
var a = [42, 7, -5, 11.7, 58, 22.31, 59, -18] System.print(max.call(a))</lang>
- Output:
59
XPL0
The set of values is the lengths of the lines of text in the input file.
<lang XPL0>include c:\cxpl\codes; \include 'code' declarations
def Tab=$09, LF=$0A, CR=$0D, EOF=$1A;
int CpuReg, Hand; char CmdTail($80); int I, Max, C;
[\Copy file name on command line, which is in the Program Segment Prefix (PSP) \ ES=CpuReg(11), to the CmdTail array, which is in our Data Segment = CpuReg(12) CpuReg:= GetReg; \point to copy of CPU registers Blit(CpuReg(11), $81, CpuReg(12), CmdTail, $7F); Hand:= FOpen(CmdTail, 0); \open file for input and get its handle FSet(Hand, ^I); \assign handle to device 3 OpenI(3); \initialize file for input
Max:= 0; \scan file for longest line repeat I:= 0;
repeat C:= ChIn(3);
case C of
CR, LF, EOF: []; \don't count these characters
Tab: [I:= I+8 & ~7] \(every 8th column)
other I:= I+1; \count all other characters
until C=LF or C=EOF;
if I > Max then Max:= I;
until C = EOF; Text(0, "Longest line = "); IntOut(0, Max); CrLf(0); ]</lang>
Example of running the program on its source code:
maxline maxline.xpl Longest line = 80
XSLT
The desired value is the first in a sequence that has been sorted numerically in descending order. <lang xml><xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0"> <xsl:output method="text"/>
<xsl:template match="/"> <xsl:for-each select="/*/*"> <xsl:sort data-type="number" order="descending"/> <xsl:if test="position() = 1"> <xsl:value-of select="."/> </xsl:if> </xsl:for-each> </xsl:template> </xsl:stylesheet></lang>
Sample input:
<lang xml><numbers> <number>3</number> <number>1</number> <number>12</number> <number>7</number> </numbers></lang>
- Output:
12
Yabasic
<lang Yabasic>l$ = "1,1234,62,234,12,34,6"
dim n$(1)
n = token(l$, n$(), ", ")
for i = 1 to n t$ = n$(i) if t$ > m$ then m$ = t$ end if // or: if t$ > m$ m$ = t$ if val(t$) > m then m = val(t$) end if // or: if val(t$) > m m = val(t$) next
print "Alphabetic order: ", m$, ", numeric order: ", m</lang>
Yacas
Input: <lang Yacas>Max({1, 3, 3, 7}) Max({Pi,Exp(1)+2/5,17*Cos(6)/5,Sqrt(91/10)}) Max({1,6,Infinity}) Max({})</lang>
- Output:
7 (17*Cos(2*Pi-6))/5 Infinity Undefined
Yorick
The built-in function max does this. Interactive example:
> foo = [4, 3, 2, 7, 8, 9] > max(foo) 9
zkl
<lang zkl>(1).max(1,2,3) //-->3 (66).max(1,2,3.14) //-->66</lang> If given a list, the max of the list is returned. The number/object just selects the method to call. Notice the difference between Int.max and Float.max. <lang zkl>(66).max(T(1,2,3)) //-->3 (66).max(T(1,2,3.14)) //-->3 (6.6).max(T(1,2,3.14)) //-->3.14</lang> For other object types, you could use: <lang zkl>fcn max{ vm.arglist.reduce(fcn(p,n){ if(p < n) n else p }) }</lang>
max(2,1,-40,50,2,4,2) //-->50
max(2) //-->2
max("foo","bar") //-->"foo"
max("3",4,"5") //-->"5" only if strings contain only digits
Zoea
<lang Zoea> program: max
case: 1
input: [7,3,5,9,2,6]
output: 9
case: 2
input: [1,5,3,2,7]
output: 7
</lang>
ZX Spectrum Basic
<lang zxbasic>10 PRINT "Values" 20 LET z=0 30 FOR x=1 TO INT (RND*10)+1 40 LET y=RND*10-5 50 PRINT y 60 LET z=(y AND y>z)+(z AND y<z) 70 NEXT x 80 PRINT '"Max. value = ";z</lang>
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