Largest int from concatenated ints: Difference between revisions
Content added Content deleted
Drkameleon (talk | contribs) (Replaced content with "=={{header|Arturo}}== <lang rebol>largestConcInt: function [arr]-> max map permutate arr 's [ to :integer join map s => [to :string] ] loop 1 34 3 98 9...") |
(Undo revision 324515 by Drkameleon (talk) Whole page taken out by mistake when adding Arturo solution.) |
||
Line 1: | Line 1: | ||
{{task}} |
|||
=={{header|Arturo}}== |
|||
<lang rebol>largestConcInt: function [arr]-> |
|||
;Task: |
|||
max map permutate arr 's [ |
|||
Given a set of positive integers, write a function to order the integers in such a way that the concatenation of the numbers forms the largest possible integer and return this integer. |
|||
to :integer join map s => [to :string] |
|||
Use the following two sets of integers as tests and show your program output here. |
|||
:::::* {1, 34, 3, 98, 9, 76, 45, 4} |
|||
:::::* {54, 546, 548, 60} |
|||
<br> |
|||
;Possible algorithms: |
|||
# A solution could be found by trying all combinations and return the best. |
|||
# Another way to solve this is to note that in the best arrangement, for any two adjacent original integers '''X''' and '''Y''', the concatenation '''X''' followed by '''Y''' will be numerically greater than or equal to the concatenation '''Y''' followed by '''X. |
|||
# Yet another way to solve this is to pad the integers to the same size by repeating the digits then sort using these repeated integers as a sort key. |
|||
;See also: |
|||
* [http://www.quora.com/Algorithms/What-is-the-most-efficient-way-to-arrange-the-given-numbers-to-form-the-biggest-number Algorithms: What is the most efficient way to arrange the given numbers to form the biggest number?] |
|||
* [http://stackoverflow.com/questions/14532105/constructing-the-largest-number-possible-by-rearranging-a-list/14539943#14539943 Constructing the largest number possible by rearranging a list] |
|||
<br><br> |
|||
=={{header|11l}}== |
|||
{{trans|Python}} |
|||
<lang 11l>F maxnum(x) |
|||
V maxlen = String(max(x)).len |
|||
R sorted((x.map(v -> String(v))), key' i -> i * (@maxlen * 2 I/ i.len), reverse' 1B).join(‘’) |
|||
L(numbers) [[212, 21221], [1, 34, 3, 98, 9, 76, 45, 4], [54, 546, 548, 60]] |
|||
print("Numbers: #.\n Largest integer: #15".format(numbers, maxnum(numbers)))</lang> |
|||
{{out}} |
|||
<pre> |
|||
Numbers: [212, 21221] |
|||
Largest integer: 21221221 |
|||
Numbers: [1, 34, 3, 98, 9, 76, 45, 4] |
|||
Largest integer: 998764543431 |
|||
Numbers: [54, 546, 548, 60] |
|||
Largest integer: 6054854654 |
|||
</pre> |
|||
=={{header|Ada}}== |
|||
The algorithmic idea is to apply a twisted comparison function: |
|||
<lang Ada>function Order(Left, Right: Natural) return Boolean is |
|||
( (Img(Left) & Img(Right)) > (Img(Right) & Img(Left)) );</lang> |
|||
This function converts the parameters Left and Right to strings and returns True if (Left before Right) |
|||
exceeds (Right before Left). It needs Ada 2012 -- the code for older versions of Ada would be more verbose. |
|||
The rest is straightforward: Run your favourite sorting subprogram that allows to use the function "Order" instead of standard comparison operators ("<" or ">" or so) and print the results: |
|||
<lang Ada>with Ada.Text_IO, Ada.Containers.Generic_Array_Sort; |
|||
procedure Largest_Int_From_List is |
|||
function Img(N: Natural) return String is |
|||
S: String := Integer'Image(N); |
|||
begin |
|||
return S(S'First+1 .. S'Last); -- First character is ' ' |
|||
end Img; |
|||
function Order(Left, Right: Natural) return Boolean is |
|||
( (Img(Left) & Img(Right)) > (Img(Right) & Img(Left)) ); |
|||
type Arr_T is array(Positive range <>) of Natural; |
|||
procedure Sort is new Ada.Containers.Generic_Array_Sort |
|||
(Positive, Natural, Arr_T, Order); |
|||
procedure Print_Sorted(A: Arr_T) is |
|||
B: Arr_T := A; |
|||
begin |
|||
Sort(B); |
|||
for Number of B loop |
|||
Ada.Text_IO.Put(Img(Number)); |
|||
end loop; |
|||
Ada.Text_IO.New_Line; |
|||
end Print_Sorted; |
|||
begin |
|||
Print_Sorted((1, 34, 3, 98, 9, 76, 45, 4)); |
|||
Print_Sorted((54, 546, 548, 60)); |
|||
end Largest_Int_From_List;</lang> |
|||
=={{header|Aime}}== |
|||
<lang aime>largest(...) |
|||
{ |
|||
index x; |
|||
for (, integer e in xcall(list).__list) { |
|||
x[999999999 - 9.times(b_, data(), e).b_size(9).atoi] = e; |
|||
} |
|||
x.ucall(o_, 0); |
|||
o_newline(); |
|||
} |
|||
main(void) |
|||
{ |
|||
largest(1, 34, 3, 98, 9, 76, 45, 4); |
|||
largest(54, 546, 548, 60); |
|||
0; |
|||
}</lang> |
|||
works for input up to 999999999. |
|||
{{Out}} |
|||
<pre>998764543431 |
|||
6054854654</pre> |
|||
=={{header|ALGOL 68}}== |
|||
Using method 2 - first sorting into first digit order and then comparing concatenated pairs. |
|||
<lang algol68>BEGIN |
|||
# returns the integer value of s # |
|||
OP TOINT = ( STRING s)INT: |
|||
BEGIN |
|||
INT result := 0; |
|||
FOR s pos FROM LWB s TO UPB s DO |
|||
result *:= 10 +:= ( ABS s[ s pos ] - ABS "0" ) |
|||
OD; |
|||
result |
|||
END # TOINT # ; |
|||
# returns the first digit of n # |
|||
OP FIRSTDIGIT = ( INT n )INT: |
|||
BEGIN |
|||
INT result := ABS n; |
|||
WHILE result > 9 DO result OVERAB 10 OD; |
|||
result |
|||
END # FIRSTDIGIT # ; |
|||
# returns a string representaton of n # |
|||
OP TOSTRING = ( INT n )STRING: whole( n, 0 ); |
|||
# returns an array containing the values of a sorted such that concatenating the values would result in the largest value # |
|||
OP CONCATSORT = ( []INT a )[]INT: |
|||
IF LWB a >= UPB a THEN |
|||
# 0 or 1 element(s) # |
|||
a |
|||
ELSE |
|||
# 2 or more elements # |
|||
[ 1 : ( UPB a - LWB a ) + 1 ]INT result := a[ AT 1 ]; |
|||
# sort the numbers into reverse first digit order # |
|||
FOR o pos FROM UPB result - 1 BY -1 TO 1 |
|||
WHILE BOOL swapped := FALSE; |
|||
FOR i pos TO o pos DO |
|||
IF FIRSTDIGIT result[ i pos ] < FIRSTDIGIT result[ i pos + 1 ] THEN |
|||
INT t = result[ i pos + 1 ]; |
|||
result[ i pos + 1 ] := result[ i pos ]; |
|||
result[ i pos ] := t; |
|||
swapped := TRUE |
|||
FI |
|||
OD; |
|||
swapped |
|||
DO SKIP OD; |
|||
# now re-order adjacent numbers so they have the highest concatenated value # |
|||
WHILE BOOL swapped := FALSE; |
|||
FOR i pos TO UPB result - 1 DO |
|||
STRING l := TOSTRING result[ i pos ]; |
|||
STRING r := TOSTRING result[ i pos + 1 ]; |
|||
IF TOINT ( l + r ) < TOINT ( r + l ) THEN |
|||
INT t = result[ i pos + 1 ]; |
|||
result[ i pos + 1 ] := result[ i pos ]; |
|||
result[ i pos ] := t; |
|||
swapped := TRUE |
|||
FI |
|||
OD; |
|||
swapped |
|||
DO SKIP OD; |
|||
result |
|||
FI # CONCATSORT # ; |
|||
# prints the array a # |
|||
OP PRINT = ( []INT a )VOID: |
|||
FOR a pos FROM LWB a TO UPB a DO |
|||
print( ( TOSTRING a[ a pos ] ) ) |
|||
OD # PRINT # ; |
|||
# task test cases # |
|||
PRINT CONCATSORT []INT( 1, 34, 3, 98, 9, 76, 45, 4 ); |
|||
print( ( newline ) ); |
|||
PRINT CONCATSORT []INT( 54, 546, 548, 60 ); |
|||
print( ( newline ) ) |
|||
END</lang> |
|||
{{out}} |
|||
<pre> |
|||
998764543431 |
|||
6054854654 |
|||
</pre> |
|||
=={{header|AutoHotkey}}== |
|||
<lang AutoHotkey>LargestConcatenatedInts(var){ |
|||
StringReplace, var, A_LoopField,%A_Space%,, all |
|||
Sort, var, D`, fConcSort |
|||
StringReplace, var, var, `,,, all |
|||
return var |
|||
} |
|||
ConcSort(a, b){ |
|||
m := a . b , n := b . a |
|||
return m < n ? 1 : m > n ? -1 : 0 |
|||
}</lang> |
|||
Examples:<lang AutoHotkey>d = |
|||
( |
|||
1, 34, 3, 98, 9, 76, 45, 4 |
|||
54, 546, 548, 60 |
|||
4 , 45, 54, 5 |
|||
) |
|||
loop, parse, d, `n |
|||
MsgBox % LargestConcatenatedInts(A_LoopField)</lang> |
|||
{{out}} |
|||
<pre>998764543431 |
|||
6054854654 |
|||
554454</pre> |
|||
=={{header|AWK}}== |
|||
{{works with|gawk|4.0}} |
|||
<lang awk> |
|||
function cmp(i1, v1, i2, v2, u1, u2) { |
|||
u1 = v1""v2; |
|||
u2 = v2""v1; |
|||
return (u2 - u1) |
|||
} |
|||
function largest_int_from_concatenated_ints(X) { |
|||
PROCINFO["sorted_in"]="cmp"; |
|||
u=""; |
|||
for (i in X) u=u""X[i]; |
|||
return u |
|||
} |
|||
BEGIN { |
|||
split("1 34 3 98 9 76 45 4",X); |
|||
print largest_int_from_concatenated_ints(X) |
|||
split("54 546 548 60",X); |
|||
print largest_int_from_concatenated_ints(X) |
|||
} |
|||
</lang> |
|||
{{out}} |
|||
<pre>998764543431 |
|||
6054854654</pre> |
|||
=={{header|BBC BASIC}}== |
|||
<lang bbcbasic> DIM Nums%(10) |
|||
Nums%()=1,34,3,98,9,76,45,4 |
|||
PRINT FNlargestint(8) |
|||
Nums%()=54,546,548,60 |
|||
PRINT FNlargestint(4) |
|||
END |
|||
DEF FNlargestint(len%) |
|||
LOCAL i%,l$,a$,b$,sorted% |
|||
REPEAT |
|||
sorted%=TRUE |
|||
FOR i%=0 TO len%-2 |
|||
a$=STR$Nums%(i%) |
|||
b$=STR$Nums%(i%+1) |
|||
IF a$+b$<b$+a$ SWAP Nums%(i%),Nums%(i%+1):sorted%=FALSE |
|||
NEXT |
|||
UNTIL sorted% |
|||
FOR i%=0 TO len%-1 |
|||
l$+=STR$Nums%(i%) |
|||
NEXT |
|||
=l$</lang> |
|||
{{out}} |
|||
<pre>998764543431 |
|||
6054854654</pre> |
|||
=={{header|Bracmat}}== |
|||
<lang bracmat>( ( maxnum |
|||
= A Z F C |
|||
. !arg:# |
|||
| !arg |
|||
: %@?F |
|||
? |
|||
( #%@?C |
|||
& ( str$(!F !C)+-1*str$(!C !F):~<0 |
|||
| !C:?F |
|||
) |
|||
& ~ |
|||
) |
|||
? |
|||
| !arg:?A !F ?Z&!F maxnum$(!A !Z) |
|||
) |
|||
& out$(str$(maxnum$(1 34 3 98 9 76 45 4))) |
|||
& out$(str$(maxnum$(54 546 548 60))) |
|||
);</lang> |
|||
{{out}} |
|||
<pre>998764543431 |
|||
6054854654</pre> |
|||
=={{header|C}}== |
|||
<lang C>#include <stdio.h> |
|||
#include <stdlib.h> |
|||
#include <string.h> |
|||
int catcmp(const void *a, const void *b) |
|||
{ |
|||
char ab[32], ba[32]; |
|||
sprintf(ab, "%d%d", *(int*)a, *(int*)b); |
|||
sprintf(ba, "%d%d", *(int*)b, *(int*)a); |
|||
return strcmp(ba, ab); |
|||
} |
|||
void maxcat(int *a, int len) |
|||
{ |
|||
int i; |
|||
qsort(a, len, sizeof(int), catcmp); |
|||
for (i = 0; i < len; i++) |
|||
printf("%d", a[i]); |
|||
putchar('\n'); |
|||
} |
|||
int main(void) |
|||
{ |
|||
int x[] = {1, 34, 3, 98, 9, 76, 45, 4}; |
|||
int y[] = {54, 546, 548, 60}; |
|||
maxcat(x, sizeof(x)/sizeof(x[0])); |
|||
maxcat(y, sizeof(y)/sizeof(y[0])); |
|||
return 0; |
|||
}</lang> |
|||
{{out}} |
|||
<pre>998764543431 |
|||
6054854654</pre> |
|||
=={{header|C sharp|C#}}== |
|||
<lang csharp>using System; |
|||
using System.Collections.Generic; |
|||
using System.Linq; |
|||
class Program |
|||
{ |
|||
static void Main(string[] args) |
|||
{ |
|||
var source1 = new int[] { 1, 34, 3, 98, 9, 76, 45, 4 }; |
|||
var source2 = new int[] { 54, 546, 548, 60 }; |
|||
var largest1 = LargestPossibleSequence(source1); |
|||
var largest2 = LargestPossibleSequence(source2); |
|||
Console.WriteLine("The largest possible integer from set 1 is: {0}", largest1); |
|||
Console.WriteLine("The largest possible integer from set 2 is: {0}", largest2); |
|||
} |
|||
static long LargestPossibleSequence(int[] ints) |
|||
{ |
|||
return long.Parse(string.Join("", ints.OrderBy(i => i, new IntConcatenationComparer()).Reverse())); |
|||
} |
|||
} |
|||
class IntConcatenationComparer : IComparer<int> |
|||
{ |
|||
public int Compare(int x, int y) |
|||
{ |
|||
var xy = int.Parse(x.ToString() + y.ToString()); |
|||
var yx = int.Parse(y.ToString() + x.ToString()); |
|||
return xy - yx; |
|||
} |
|||
} |
|||
</lang> |
|||
{{out}} |
|||
<pre>The largest possible integer from set 1 is: 998764543431 |
|||
The largest possible integer from set 2 is: 6054854654</pre> |
|||
=={{header|C++}}== |
|||
<lang cpp>#include <iostream> |
|||
#include <sstream> |
|||
#include <algorithm> |
|||
#include <vector> |
|||
#include <string> |
|||
std::string findLargestConcat ( std::vector< int > & mynumbers ) { |
|||
std::vector<std::string> concatnumbers ; |
|||
std::sort ( mynumbers.begin( ) , mynumbers.end( ) ) ; |
|||
do { |
|||
std::ostringstream numberstream ; |
|||
for ( int i : mynumbers ) |
|||
numberstream << i ; |
|||
concatnumbers.push_back( numberstream.str( ) ) ; |
|||
} while ( std::next_permutation( mynumbers.begin( ) , |
|||
mynumbers.end( ) )) ; |
|||
return *( std::max_element( concatnumbers.begin( ) , |
|||
concatnumbers.end( ) ) ) ; |
|||
} |
|||
int main( ) { |
|||
std::vector<int> mynumbers = { 98, 76 , 45 , 34, 9 , 4 , 3 , 1 } ; |
|||
std::vector<int> othernumbers = { 54 , 546 , 548 , 60 } ; |
|||
std::cout << "The largest concatenated int is " << |
|||
findLargestConcat( mynumbers ) << " !\n" ; |
|||
std::cout << "And here it is " << findLargestConcat( othernumbers ) |
|||
<< " !\n" ; |
|||
return 0 ; |
|||
}</lang> |
|||
{{out}} |
|||
<pre>The largest concatenated int is 998764543431 ! |
|||
And here it is 6054854654 !</pre> |
|||
=={{header|Ceylon}}== |
|||
{{trans|Kotlin}} |
|||
{{works with|Ceylon|1.3.3}} |
|||
<lang ceylon>shared void run() { |
|||
function comparator(Integer x, Integer y) { |
|||
assert (is Integer xy = Integer.parse(x.string + y.string), |
|||
is Integer yx = Integer.parse(y.string + x.string)); |
|||
return yx <=> xy; |
|||
} |
|||
function biggestConcatenation({Integer*} ints) => "".join(ints.sort(comparator)); |
|||
value test1 = {1, 34, 3, 98, 9, 76, 45, 4}; |
|||
print(biggestConcatenation(test1)); |
|||
value test2 = {54, 546, 548, 60}; |
|||
print(biggestConcatenation(test2)); |
|||
}</lang> |
|||
=={{header|Clojure}}== |
|||
<lang Clojure>(defn maxcat [coll] |
|||
(read-string |
|||
(apply str |
|||
(sort (fn [x y] |
|||
(apply compare |
|||
(map read-string [(str y x) (str x y)]))) |
|||
coll)))) |
|||
(prn (map maxcat [[1 34 3 98 9 76 45 4] [54 546 548 60]]))</lang> |
|||
{{out}} |
|||
<pre>(998764543431 6054854654)</pre> |
|||
=={{header|Common Lisp}}== |
|||
=== Sort by two-by-two comparison of largest concatenated result === |
|||
<lang lisp> |
|||
(defun int-concat (ints) |
|||
(read-from-string (format nil "~{~a~}" ints))) |
|||
(defun by-biggest-result (first second) |
|||
(> (int-concat (list first second)) (int-concat (list second first)))) |
|||
(defun make-largest-int (ints) |
|||
(int-concat (sort ints #'by-biggest-result))) |
|||
</lang> |
|||
{{out}} |
|||
<pre> |
|||
> (make-largest-int '(1 34 3 98 9 76 45 4)) |
|||
998764543431 |
|||
> (make-largest-int '(54 546 548 60)) |
|||
6054854654 |
|||
</pre> |
|||
=== Variation around the sort with padded most significant digit === |
|||
<lang lisp> |
|||
;; Sort criteria is by most significant digit with least digits used as a tie |
|||
;; breaker |
|||
(defun largest-msd-with-less-digits (x y) |
|||
(flet ((first-digit (x) |
|||
(digit-char-p (aref x 0)))) |
|||
(cond ((> (first-digit x) |
|||
(first-digit y)) |
|||
t) |
|||
((> (first-digit y) |
|||
(first-digit x)) |
|||
nil) |
|||
((and (= (first-digit x) |
|||
(first-digit y)) |
|||
(> (length x) |
|||
(length y))) |
|||
nil) |
|||
(t t)))) |
|||
(loop |
|||
:for input :in '((54 546 548 60) (1 34 3 98 9 76 45 4)) |
|||
:do (format t "~{~A~}~%" |
|||
(sort (mapcar #'write-to-string input) |
|||
#'largest-msd-with-less-digits))) |
|||
</lang> |
|||
{{out}} |
|||
<pre> |
|||
6054548546 |
|||
998764453341 |
|||
</pre> |
|||
=={{header|D}}== |
|||
The three algorithms. Uses the second module from the Permutations Task. |
|||
<lang d>import std.stdio, std.algorithm, std.conv, std.array, permutations2; |
|||
auto maxCat1(in int[] arr) pure @safe { |
|||
return arr.to!(string[]).permutations.map!join.reduce!max; |
|||
} |
|||
auto maxCat2(in int[] arr) pure nothrow @safe { |
|||
return arr.to!(string[]).sort!q{b ~ a < a ~ b}.join; |
|||
} |
|||
auto maxCat3(in int[] arr) /*pure nothrow @safe*/ { |
|||
immutable maxL = arr.reduce!max.text.length; |
|||
return arr.to!(string[]) |
|||
.schwartzSort!(s => s.replicate(maxL/s.length + 1), "a > b") |
|||
.join; |
|||
} |
|||
void main() { |
|||
const lists = [[1, 34, 3, 98, 9, 76, 45, 4], [54, 546, 548, 60]]; |
|||
[&maxCat1, &maxCat2, &maxCat3].map!(cat => lists.map!cat).writeln; |
|||
}</lang> |
|||
{{out}} |
|||
<pre>[["998764543431", "6054854654"], ["998764543431", "6054854654"], ["998764543431", "6054854654"]]</pre> |
|||
=={{header|Elixir}}== |
|||
<lang elixir>defmodule RC do |
|||
def largest_int(list) do |
|||
sorted = Enum.sort(list, fn x,y -> "#{x}#{y}" >= "#{y}#{x}" end) |
|||
Enum.join(sorted) |
|||
end |
|||
end |
|||
IO.inspect RC.largest_int [1, 34, 3, 98, 9, 76, 45, 4] |
|||
IO.inspect RC.largest_int [54, 546, 548, 60]</lang> |
|||
{{out}} |
|||
<pre> |
|||
"998764543431" |
|||
"6054854654" |
|||
</pre> |
|||
=={{header|Erlang}}== |
|||
<lang Erlang> |
|||
-module( largest_int_from_concatenated ). |
|||
-export( [ints/1, task/0] ). |
|||
ints( Ints ) -> |
|||
Int_strings = [erlang:integer_to_list(X) || X <- Ints], |
|||
Pad_ints = [{X ++ X, X} || X <- Int_strings], |
|||
erlang:list_to_integer( lists:append([Int || {_Pad, Int} <- lists:reverse(lists:sort(Pad_ints))]) ). |
|||
task() -> |
|||
[io:fwrite("Largest ~p from ~p~n", [ints(X), X]) || X <- [[1, 34, 3, 98, 9, 76, 45, 4], [54, 546, 548, 60]]]. |
|||
</lang> |
|||
{{out}} |
|||
<pre> |
|||
8> largest_int_from_concatenated:task(). |
|||
Largest 998764543431 from [1,34,3,98,9,76,45,4] |
|||
Largest 6054854654 from [54,546,548,60] |
|||
</pre> |
|||
=={{header|F_Sharp|F#}}== |
|||
<lang fsharp> |
|||
// Form largest integer which is a permutation from a list of integers. Nigel Galloway: March 21st., 2018 |
|||
let fN g = List.map (string) g |> List.sortWith(fun n g->if n+g<g+n then 1 else -1) |> System.String.Concat |
|||
</lang> |
|||
{{out}} |
|||
<pre> |
|||
fN [1; 34; 3; 98; 9; 76; 45; 4] -> "998764543431" |
|||
fN [54; 546; 548; 60] -> "6054854654" |
|||
</pre> |
|||
=={{header|Factor}}== |
|||
Using algorithm 3: |
|||
<lang factor>USING: assocs io kernel math qw sequences sorting ; |
|||
IN: rosetta-code.largest-int |
|||
: pad ( target seq -- padded ) |
|||
2dup length / swap <repetition> concat swap head ; |
|||
: largest-int ( seq -- ) |
|||
dup dup [ length ] map supremum ! find longest length so we know how much to pad |
|||
[ swap pad ] curry map ! pad the integers |
|||
<enum> sort-values ! sort the padded integers |
|||
keys ! find the original indices of the sorted integers |
|||
swap nths ! order non-padded integers according to their sorted order |
|||
reverse concat print ; |
|||
qw{ 1 34 3 98 9 76 45 4 } qw{ 54 546 548 60 } [ largest-int ] bi@</lang> |
|||
{{out}} |
|||
<pre> |
|||
998764543431 |
|||
6054854654 |
|||
</pre> |
|||
Or alternatively, a translation of F#. |
|||
{{trans|F#}} |
|||
<lang factor>USING: kernel math.order qw sequences sorting ; |
|||
: fn ( seq -- str ) |
|||
[ 2dup swap [ append ] 2bi@ after? +lt+ +gt+ ? ] sort concat ;</lang> |
|||
{{out}} |
|||
<pre> |
|||
qw{ 1 34 3 98 9 76 45 4 } qw{ 54 546 548 60 } [ fn ] bi@ |
|||
--- Data stack: |
|||
"998764543431" |
|||
"6054854654"</pre> |
|||
=={{header|Fortran}}== |
|||
There is often a potential ambiguity when reading numbers. While three definitely names the Platonic number notion, 3 might instead be regarded as being a text that happens to have the glyph of a number but is not a number. This sort of discussion arises when a spreadsheet has read in a text file and behold! numbers are on the display and they look just like what is displayed when numbers are being shown, but, they are ''not'' numbers, they are only drawn that way. Within the spreadsheet they are parts of some text, and the notion that takes over is one of a "blunt, heavy object", not alas close to hand. |
|||
So, the plan is to regard the numbers as being text sequences aligned to the left, containing only digit characters of course - except for the fact that CHARACTER variables often end up having trailing spaces. F2003 formalised a scheme whereby such variables can be "cut-to-fit" as execution proceeds but with earlier Fortrans the standard method is to pay attention to the number of characters in use. F90 introduced a function LEN_TRIM(text) to return the index of the last non-blank character in a text so the only problem now is to decide on how long might the largest number be (and by representing numbers as text strings, there is no difficulty with the limits of INTEGER*2 or INTEGER*4 ''etc.''), and what will be the maximum number of numbers. By devising a subroutine to do the work, these issues can be handled by the caller that is providing the data. The subroutine however intends to sort the collection of texts. This could be done by damaging its parameter which might be regarded as impolite or even unwanted so instead the sort is effected via an array XLAT and juggling its values. This has the advantage that the possibly large elements of the text array are not being moved about, but means that the subroutine must be able to have an XLAT array that is "large enough". F90 standardised the ability for a routine to declare such an array at run-time; previously, arrays within a subroutine (or indeed anywhere) had to have a size fixed at compilation time. In the past this might have been handled by the caller supplying such an array as an additional parameter. |
|||
Passing arrays as parameters can be tricky, especially for multi-dimensional arrays. This uses the old style whereby the size is left unstated via the * in <code>TEXT(*)</code>, though one could use <code>TEXT(N)</code> instead - but at the risk that the actual value of N is wrong and array index checking might be confused thereby. Still earlier one would simply place some integer value there, any valid integer, as in <code>TEXT(666)</code>, and not worry about bound checking at all because old-style compilers did not produce checking code even if it was wanted. F90 standardised the MODULE protocol, within which the size is specified as <code>TEXT(:)</code> whereby secret additional parameters are supplied that contain the actual bound information and bound checking will be correct, possibly not so if the <code>TEXT(N)</code> form is used instead and N is wrong. This extra overhead in every use is possibly better than undetected errors in some uses... |
|||
The sorting of the text array was to be by the notorious BubbleSort, taking advantage of the fact that each pass delivers the maximum value of the unsorted portion to its final position: the output could thereby be produced as the sort worked. Rather than mess about with early termination (no element being swapped) or attention to the bounds within which swapping took place, attention concentrated upon the comparison. Because of the left-alignment of the texts, a simple comparison seemed sufficient until I thought of unequal text lengths and then the following example. Suppose there are two numbers, 5, and one of 54, 55, or 56 as the other. Via normal comparisons, the 5 would always be first (because short texts are considered expanded with trailing spaces when compared against longer texts, and a space precedes every digit) however the biggest ordering is 5 54 for the first case but 56 5 for the last. This possibility is not exemplified in the specified trial sets. So, a more complex comparison is required. One could of course write a suitable function and consider the issue there but instead the comparison forms the compound text in the same manner as the result will be, in the two ways AB and BA, and looks to see which yields the bigger sequence. This need only be done for unequal length text pairs. |
|||
The source is F77 style, except for the declaration of XLAT(N), the use of <N> in the FORMAT statements instead of some large constant or similar, and the ability to declare an array via constants as in <code>(/"5","54"/)</code> rather than mess about declaring arrays and initialising them separately. The <code>I0</code> format code to convert a number (an actual number) into a digit string aligned leftwards in a CHARACTER variable of sufficient size is also a F90 introduction, though the B6700 compiler allowed a code <code>J</code> instead. This last is to demonstrate usage of actual numbers for those unpersuaded by the argument for ambiguity that allows for texts. If the <code>I0</code> format code is unavailable then <code>I9</code> (or some suitable size) could be used, followed by <code>text = ADJUSTL(text)</code>, except that this became an intrinsic function only in F90, so perhaps you will have to write a simple alignment routine. <lang Fortran> SUBROUTINE SWAP(A,B) !Why can't the compiler supply these! |
|||
INTEGER A,B,T |
|||
T = B |
|||
B = A |
|||
A = T |
|||
END |
|||
SUBROUTINE BIGUP(TEXT,N) !Outputs the numbers in TEXT to give the biggest number. |
|||
CHARACTER*(*) TEXT(*) !The numbers as text, aligned left. |
|||
INTEGER N !The number of them. |
|||
INTEGER XLAT(N),L(N) !An index and a set of lengths. |
|||
INTEGER I,J,M !Assorted steppers. |
|||
INTEGER TI,TJ !Fingers to a text. |
|||
INTEGER LI,LJ !Lengths of the fingered texts. |
|||
INTEGER MSG !I/O unit number. |
|||
COMMON /IODEV/ MSG !Old style. |
|||
DO I = 1,N !Step through my supply of texts. |
|||
XLAT(I) = I !Preparing a finger to them. |
|||
L(I) = LEN_TRIM(TEXT(I)) !And noting their last non-blank. |
|||
END DO !On to the next. |
|||
WRITE (MSG,1) "Supplied",(TEXT(I)(1:L(I)), I = 1,N) !Show the grist. |
|||
1 FORMAT (A12,":",<N>(A,",")) !Instead of <N>, 666 might suffice. |
|||
Crude bubblesort. No attempt at noting the bounds of swaps made. |
|||
DO M = N,1,-1 !Just for fun, go backwards. |
|||
DO I = 2,M !Start a scan. |
|||
J = I - 1 !Comparing element I to element I - 1. |
|||
TI = XLAT(I) !Thus finger the I'th text in XLAT order. |
|||
TJ = XLAT(J) !And its supposed predecessor. |
|||
LI = L(TI) !The length of the fingered text. |
|||
LJ = L(TJ) !All this to save on typing below. |
|||
IF (LI .EQ. LJ) THEN !If the texts are equal lengths, |
|||
IF (TEXT(TI).LT.TEXT(TJ)) CALL SWAP(XLAT(I),XLAT(J)) !A simple comparison. |
|||
ELSE !But if not, construct the actual candidate texts for comparison. |
|||
IF (TEXT(TI)(1:LI)//TEXT(TJ)(1:LJ) !These two will be the same length. |
|||
1 .LT.TEXT(TJ)(1:LJ)//TEXT(TI)(1:LI)) !Just as above. |
|||
2 CALL SWAP(XLAT(I),XLAT(J)) !J shall now follow I. |
|||
END IF !So much for that comparison. |
|||
END DO !On to the next. |
|||
END DO !The original plan was to reveal element XLAT(M) as found. |
|||
WRITE (MSG,2) "Biggest",(TEXT(XLAT(I))(1:L(XLAT(I))),I = N,1,-1) !But, all at once is good too. |
|||
2 FORMAT (A12,":",<N>(A," ")) !The space maintains identity. |
|||
END !That was fun. |
|||
PROGRAM POKE |
|||
CHARACTER*4 T1(10) !Prepare some example arrays. |
|||
CHARACTER*4 T2(4) !To hold the specified examples. |
|||
INTEGER MSG |
|||
COMMON /IODEV/ MSG |
|||
DATA T1(1:8)/"1","34","3","98","9","76","45","4"/ |
|||
DATA T2/"54","546","548","60"/ |
|||
MSG = 6 !Standard output. |
|||
WRITE (MSG,1) |
|||
1 FORMAT ("Takes a list of integers and concatenates them so as ", |
|||
1 "to produce the biggest possible number.",/, |
|||
2 "The result is shown with spaces between the parts ", |
|||
3 "to show provenance. Ignore them otherwise."/) |
|||
CALL BIGUP(T1,8) |
|||
WRITE (MSG,*) |
|||
CALL BIGUP(T2,4) |
|||
WRITE (MSG,*) "These are supplied in lexicographical order..." |
|||
CALL BIGUP((/"5","54"/),2) |
|||
WRITE (MSG,*) "But this is not necessarily the biggest order." |
|||
CALL BIGUP((/"5","56"/),2) |
|||
WRITE (MSG,*) "And for those who count..." |
|||
DO I = 1,10 |
|||
WRITE (T1(I),"(I0)") I !This format code produces only the necessary text. |
|||
END DO !Thus, the numbers are aligned left in the text field. |
|||
CALL BIGUP(T1,10) |
|||
END </lang> |
|||
Output: the Fortran compiler ignores spaces when reading fortran source, so, hard-core fortranners should have no difficulty doing likewise for the output... |
|||
<pre> |
|||
Takes a list of integers and concatenates them so as to produce the biggest possible number. |
|||
The result is shown with spaces between the parts to show provenance. Ignore them otherwise. |
|||
Supplied:1,34,3,98,9,76,45,4, |
|||
Biggest:9 98 76 45 4 34 3 1 |
|||
Supplied:54,546,548,60, |
|||
Biggest:60 548 546 54 |
|||
These are supplied in lexicographical order... |
|||
Supplied:5,54, |
|||
Biggest:5 54 |
|||
But this is not necessarily the biggest order. |
|||
Supplied:5,56, |
|||
Biggest:56 5 |
|||
And for those who count... |
|||
Supplied:1,2,3,4,5,6,7,8,9,10, |
|||
Biggest:9 8 7 6 5 4 3 2 1 10 |
|||
</pre> |
|||
=={{header|FreeBASIC}}== |
|||
<lang freebasic>#define MAXDIGITS 8 |
|||
function catint( a as string, b as string ) as uinteger |
|||
return valint(a+b) |
|||
end function |
|||
function grt( a as string, b as string ) as boolean |
|||
return catint(a, b)>catint(b, a) |
|||
end function |
|||
sub shellsort( a() as string ) |
|||
'quick and dirty shellsort, not the focus of this exercise |
|||
dim as uinteger gap = ubound(a), i, j, n=ubound(a) |
|||
dim as string temp |
|||
do |
|||
gap = int(gap / 2.2) |
|||
for i=gap to n |
|||
temp = a(i) |
|||
j=i |
|||
while j>=gap andalso grt( a(j-gap), temp ) |
|||
a(j) = a(j - gap) |
|||
j -= gap |
|||
wend |
|||
a(j) = temp |
|||
next i |
|||
loop until gap = 1 |
|||
end sub |
|||
sub sort_and_print( a() as string ) |
|||
dim as uinteger i |
|||
dim as string outstring = "" |
|||
shellsort(a()) |
|||
for i=0 to ubound(a) |
|||
outstring = a(i)+outstring |
|||
next i |
|||
print outstring |
|||
end sub |
|||
dim as string set1(8) = {"1", "34", "3", "98", "9", "76", "45", "4"} |
|||
dim as string set2(4) = {"54", "546", "548", "60"} |
|||
sort_and_print(set1()) |
|||
sort_and_print(set2())</lang> |
|||
{{out}} |
|||
<pre>998764543431 |
|||
6054854654 |
|||
</pre> |
|||
=={{header|Gambas}}== |
|||
'''[https://gambas-playground.proko.eu/?gist=4169e7641f29ff0ae1dd202b459e60ce Click this link to run this code]''' |
|||
<lang gambas>'Largest int from concatenated ints |
|||
Public Sub Main() |
|||
Dim iList1 As Integer[] = [1, 34, 3, 98, 9, 76, 45, 4] 'Integer list 1 |
|||
Dim iList2 As Integer[] = [54, 546, 548, 60] 'Integer list 2 |
|||
Calc(iList1) 'Send List 1 to Calc routine |
|||
Calc(iList2) 'Send List 2 to Calc routine |
|||
End |
|||
'_________________________________________________________________________________________ |
|||
Public Sub Calc(iList As Integer[]) |
|||
Dim siCount1, siCount2, siCounter As Short 'Counters |
|||
Dim sList As New String[] 'To hold converted integers |
|||
Dim bTrigger As Boolean 'To trigger a found match |
|||
For Each siCount1 In iList 'For each integer in the list.. |
|||
sList.Add(Str(siCount1)) 'Convert to a string and add to sList |
|||
If Len(Str(siCount1)) > siCounter Then 'If the length of the string is greater than siCounter then.. |
|||
siCounter = Len(Str(siCount1)) 'siCounter = length of the string |
|||
End If |
|||
Next |
|||
For siCount1 = 0 To sList.Max 'For each item in sList |
|||
If Len(sList[siCount1]) < siCounter Then 'If the length of the string is less that siCounter then.. |
|||
sList[siCount1] &= Right(sList[siCount1], 1) 'Add the same digit to the string e.g. in list 1 "9" becomes "99", list 2 "54" becomes "544" |
|||
End If |
|||
Next |
|||
sList.Sort(gb.Descent) 'Sort the list in decending order |
|||
For siCount1 = 0 To sList.Max 'For each item in sList |
|||
bTrigger = False 'Set bTrigger to False |
|||
For siCount2 = 0 To iList.Max 'Loop through each item in iList |
|||
If Val(sList[siCount1]) = iList[siCount2] Then 'If the value of each is the same e.g. "98" = 98 then |
|||
bTrigger = True 'Set bTrigger to True |
|||
Continue 'Exit the loop |
|||
Endif |
|||
Next |
|||
If Not bTrigger Then 'If there was no match e.g. there is no "99" then.. |
|||
sList[siCount1] = Left(sList[siCount1], siCounter - 1) 'Strip out the end digit e.g. "99" becomes 9 again |
|||
End If |
|||
Next |
|||
Print Val(sList.Join("")) 'Join all items in sList together and print |
|||
End</lang> |
|||
Output: |
|||
<pre> |
|||
998764543431 |
|||
6054854654 |
|||
</pre> |
|||
=={{header|Go}}== |
|||
<lang go>// Variation of method 3. Repeat digits to at least the size of the longest, |
|||
// then sort as strings. |
|||
package main |
|||
import ( |
|||
"fmt" |
|||
"math/big" |
|||
"sort" |
|||
"strconv" |
|||
"strings" |
|||
) |
|||
type c struct { |
|||
i int |
|||
s, rs string |
|||
} |
|||
type cc []*c |
|||
func (c cc) Len() int { return len(c) } |
|||
func (c cc) Less(i, j int) bool { return c[j].rs < c[i].rs } |
|||
func (c cc) Swap(i, j int) { c[i], c[j] = c[j], c[i] } |
|||
// Function required by task. Takes a list of integers, returns big int. |
|||
func li(is ...int) *big.Int { |
|||
ps := make(cc, len(is)) |
|||
ss := make([]c, len(is)) |
|||
ml := 0 |
|||
for j, i := range is { |
|||
p := &ss[j] |
|||
ps[j] = p |
|||
p.i = i |
|||
p.s = strconv.Itoa(i) |
|||
if len(p.s) > ml { |
|||
ml = len(p.s) |
|||
} |
|||
} |
|||
for _, p := range ps { |
|||
p.rs = strings.Repeat(p.s, (ml+len(p.s)-1)/len(p.s)) |
|||
} |
|||
sort.Sort(ps) |
|||
s := make([]string, len(ps)) |
|||
for i, p := range ps { |
|||
s[i] = p.s |
|||
} |
|||
b, _ := new(big.Int).SetString(strings.Join(s, ""), 10) |
|||
return b |
|||
} |
|||
func main() { |
|||
fmt.Println(li(1, 34, 3, 98, 9, 76, 45, 4)) |
|||
fmt.Println(li(54, 546, 548, 60)) |
|||
}</lang> |
|||
{{out}} |
|||
<pre> |
|||
998764543431 |
|||
6054854654 |
|||
</pre> |
|||
=={{header|Groovy}}== |
|||
<lang groovy>def largestInt = { c -> c.sort { v2, v1 -> "$v1$v2" <=> "$v2$v1" }.join('') as BigInteger }</lang> |
|||
Testing: |
|||
<lang groovy>assert largestInt([1, 34, 3, 98, 9, 76, 45, 4]) == 998764543431 |
|||
assert largestInt([54, 546, 548, 60]) == 6054854654</lang> |
|||
=={{header|Haskell}}== |
|||
===Compare repeated string method=== |
|||
<lang Haskell>import Data.List (sortBy) |
|||
import Data.Ord (comparing) |
|||
main = print (map maxcat [[1,34,3,98,9,76,45,4], [54,546,548,60]] :: [Integer]) |
|||
where |
|||
sorted xs = let pad x = concat $ replicate (maxLen `div` length x + 1) x |
|||
maxLen = maximum $ map length xs |
|||
in sortBy (flip $ comparing pad) xs |
|||
maxcat = read . concat . sorted . map show</lang> |
|||
{{out}} |
|||
<pre>[998764543431,6054854654]</pre> |
|||
Since repeating numerical string "1234" is the same as taking all the digits of 1234/9999 after the decimal point, the following does essentially the same as above: |
|||
<lang haskell>import Data.List (sortBy) |
|||
import Data.Ord (comparing) |
|||
import Data.Ratio ((%)) |
|||
nines = iterate ((+9).(*10)) 9 |
|||
maxcat = foldl (\a (n,d)->a * (1 + d) + n) 0 . |
|||
sortBy (flip $ comparing $ uncurry (%)) . |
|||
map (\a->(a, head $ dropWhile (<a) nines)) |
|||
main = mapM_ (print.maxcat) [[1,34,3,98,9,76,45,4], [54,546,548,60]]</lang> |
|||
===Sort on comparison of concatenated ints method=== |
|||
<lang Haskell>import Data.List (sortBy) |
|||
main = print (map maxcat [[1,34,3,98,9,76,45,4], [54,546,548,60]] :: [Integer]) |
|||
where sorted = sortBy (\a b -> compare (b++a) (a++b)) |
|||
maxcat = read . concat . sorted . map show</lang> |
|||
;Output as above. |
|||
===Try all permutations method=== |
|||
<lang Haskell>import Data.List (permutations) |
|||
main :: IO () |
|||
main = |
|||
print |
|||
(maxcat <$> [[1, 34, 3, 98, 9, 76, 45, 4], [54, 546, 548, 60]] :: [Integer]) |
|||
where |
|||
maxcat = read . maximum . fmap (concatMap show) . permutations</lang> |
|||
;Output as above. |
|||
=={{header|Icon}} and {{header|Unicon}}== |
|||
This solution only works in Unicon as it uses a Heap class to do the heavy |
|||
lifting. |
|||
<lang unicon>import Collections # For the Heap (dense priority queue) class |
|||
procedure main(a) |
|||
write(lici(a)) |
|||
end |
|||
procedure lici(a) |
|||
every (result := "") ||:= Heap(a,,cmp).gen() |
|||
return result |
|||
end |
|||
procedure cmp(a,b) |
|||
return (a||b) > (b||a) |
|||
end</lang> |
|||
Sample runs: |
|||
<pre> |
|||
->lici 1 34 3 98 9 76 45 4 |
|||
998764543431 |
|||
->lici 54 546 548 60 |
|||
6054854654 |
|||
-> |
|||
</pre> |
|||
=={{header|J}}== |
|||
'''Solution:''' |
|||
<lang j>maxlen=: [: >./ #&> |
|||
maxnum=: (0 ". ;)@(\: maxlen $&> ])@(8!:0)</lang> |
|||
'''Usage:''' |
|||
<lang j> maxnum&> 1 34 3 98 9 76 45 4 ; 54 546 548 60 |
|||
998764543431 6054854654</lang> |
|||
=={{header|Java}}== |
|||
{{works with|Java|1.5+}} |
|||
This example sets up a comparator to order the numbers using <code>Collections.sort</code> as described in method #3 (padding and reverse sorting). |
|||
It was also necessary to make a join method to meet the output requirements. |
|||
<lang java5>import java.util.*; |
|||
public class IntConcat { |
|||
private static Comparator<Integer> sorter = new Comparator<Integer>(){ |
|||
@Override |
|||
public int compare(Integer o1, Integer o2){ |
|||
String o1s = o1.toString(); |
|||
String o2s = o2.toString(); |
|||
if(o1s.length() == o2s.length()){ |
|||
return o2s.compareTo(o1s); |
|||
} |
|||
int mlen = Math.max(o1s.length(), o2s.length()); |
|||
while(o1s.length() < mlen * 2) o1s += o1s; |
|||
while(o2s.length() < mlen * 2) o2s += o2s; |
|||
return o2s.compareTo(o1s); |
|||
} |
|||
}; |
|||
public static String join(List<?> things){ |
|||
String output = ""; |
|||
for(Object obj:things){ |
|||
output += obj; |
|||
} |
|||
return output; |
|||
} |
|||
public static void main(String[] args){ |
|||
List<Integer> ints1 = new ArrayList<Integer>(Arrays.asList(1, 34, 3, 98, 9, 76, 45, 4)); |
|||
Collections.sort(ints1, sorter); |
|||
System.out.println(join(ints1)); |
|||
List<Integer> ints2 = new ArrayList<Integer>(Arrays.asList(54, 546, 548, 60)); |
|||
Collections.sort(ints2, sorter); |
|||
System.out.println(join(ints2)); |
|||
} |
|||
}</lang> |
|||
{{works with|Java|1.8+}} |
|||
<lang java5>import java.util.Comparator; |
|||
import java.util.stream.Collectors; |
|||
import java.util.stream.Stream; |
|||
public interface IntConcat { |
|||
public static Comparator<Integer> SORTER = (o1, o2) -> { |
|||
String o1s = o1.toString(); |
|||
String o2s = o2.toString(); |
|||
if (o1s.length() == o2s.length()) { |
|||
return o2s.compareTo(o1s); |
|||
} |
|||
int mlen = Math.max(o1s.length(), o2s.length()); |
|||
while (o1s.length() < mlen * 2) { |
|||
o1s += o1s; |
|||
} |
|||
while (o2s.length() < mlen * 2) { |
|||
o2s += o2s; |
|||
} |
|||
return o2s.compareTo(o1s); |
|||
}; |
|||
public static void main(String[] args) { |
|||
Stream<Integer> ints1 = Stream.of( |
|||
1, 34, 3, 98, 9, 76, 45, 4 |
|||
); |
|||
System.out.println(ints1 |
|||
.parallel() |
|||
.sorted(SORTER) |
|||
.map(String::valueOf) |
|||
.collect(Collectors.joining()) |
|||
); |
|||
Stream<Integer> ints2 = Stream.of( |
|||
54, 546, 548, 60 |
|||
); |
|||
System.out.println(ints2 |
|||
.parallel() |
|||
.sorted(SORTER) |
|||
.map(String::valueOf) |
|||
.collect(Collectors.joining()) |
|||
); |
|||
} |
|||
}</lang> |
|||
{{out}} |
|||
<pre>998764543431 |
|||
6054854654</pre> |
|||
=={{header|JavaScript}}== |
|||
===ES5=== |
|||
<lang JavaScript> (function () { |
|||
'use strict'; |
|||
// maxCombine :: [Int] -> Int |
|||
function maxCombine(xs) { |
|||
return parseInt( |
|||
xs.sort( |
|||
function (x, y) { |
|||
var a = x.toString(), |
|||
b = y.toString(), |
|||
ab = parseInt(a + b), |
|||
ba = parseInt(b + a); |
|||
return ab > ba ? -1 : (ab < ba ? 1 : 0); |
|||
} |
|||
) |
|||
.join(''), 10 |
|||
); |
|||
} |
|||
return [ |
|||
[1, 34, 3, 98, 9, 76, 45, 4], |
|||
[54, 546, 548, 60] |
|||
].map(maxCombine); |
|||
})(); |
|||
</lang> |
|||
{{Out}} |
|||
<pre>[998764543431, 6054854654]</pre> |
|||
===ES6=== |
|||
<lang JavaScript>var maxCombine = (a) => +(a.sort((x, y) => +("" + y + x) - +("" + x + y)).join('')); |
|||
// test & output |
|||
console.log([ |
|||
[1, 34, 3, 98, 9, 76, 45, 4], |
|||
[54, 546, 548, 60] |
|||
].map(maxCombine));</lang> |
|||
=={{header|jq}}== |
|||
{{Works with|jq|1.4}} |
|||
==== Padding ==== |
|||
''For jq versions greater than 1.4, it may be necessary to change "sort_by" to "sort".'' |
|||
<lang jq>def largest_int: |
|||
def pad(n): . + (n - length) * .[length-1:]; |
|||
map(tostring) |
|||
| (map(length) | max) as $max |
|||
| map([., pad($max)]) |
|||
| sort_by( .[1] ) |
|||
| map( .[0] ) | reverse | join("") ; |
|||
# Examples: |
|||
([1, 34, 3, 98, 9, 76, 45, 4], |
|||
[54, 546, 548, 60]) | largest_int |
|||
</lang> |
|||
{{Out}} |
|||
$ /usr/local/bin/jq -n -M -r -f Largest_int_from_concatenated_ints.jq |
|||
998764543431 |
|||
6054854654 |
|||
====Custom Sort==== |
|||
The following uses [[Sort_using_a_custom_comparator#jq| quicksort/1]]: |
|||
<lang jq>def largest_int: |
|||
map(tostring) |
|||
| quicksort( .[0] + .[1] < .[1] + .[0] ) |
|||
| reverse | join("") ;</lang> |
|||
=={{header|Julia}}== |
|||
{{works with|Julia|0.6}} |
|||
Perhaps algorithm 3 is more efficient, but algorithm 2 is decent and very easy to implement in Julia. So this solution uses algorithm 2. |
|||
<lang julia>function maxconcat(arr::Vector{<:Integer}) |
|||
b = sort(dec.(arr); lt=(x, y) -> x * y < y * x, rev=true) |> join |
|||
return try parse(Int, b) catch parse(BigInt, b) end |
|||
end |
|||
tests = ([1, 34, 3, 98, 9, 76, 45, 4], |
|||
[54, 546, 548, 60], |
|||
[1, 34, 3, 98, 9, 76, 45, 4, 54, 546, 548, 60]) |
|||
for arr in tests |
|||
println("Max concatenating in $arr:\n -> ", maxconcat(arr)) |
|||
end</lang> |
|||
{{out}} |
|||
<pre>Max concatenating in [1, 34, 3, 98, 9, 76, 45, 4]: |
|||
-> 998764543431 |
|||
Max concatenating in [54, 546, 548, 60]: |
|||
-> 6054854654 |
|||
Max concatenating in [1, 34, 3, 98, 9, 76, 45, 4, 54, 546, 548, 60]: |
|||
-> 9987660548546544543431</pre> |
|||
=={{header|Kotlin}}== |
|||
{{trans|C#}} |
|||
{{works with|Kotlin|1.0b4}} |
|||
<lang scala>import java.util.Comparator |
|||
fun main(args: Array<String>) { |
|||
val comparator = Comparator<Int> { x, y -> |
|||
val xy = (x.toString() + y).toInt() |
|||
val yx = (y.toString() + x).toInt() |
|||
xy.compareTo(yx) |
|||
} |
|||
fun findLargestSequence(array: IntArray): String { |
|||
return array.sortedWith(comparator).reversed().map { it.toString() }.joinToString("") |
|||
} |
|||
val source1 = intArrayOf(1, 34, 3, 98, 9, 76, 45, 4) |
|||
println(findLargestSequence(source1)) |
|||
val source2 = intArrayOf(54, 546, 548, 60) |
|||
println(findLargestSequence(source2)) |
|||
}</lang> |
|||
{{Out}} |
|||
998764543431 |
|||
6054854654 |
|||
=={{header|Lua}}== |
|||
{{trans|Python}} |
|||
<lang Lua>function icsort(numbers) |
|||
table.sort(numbers,function(x,y) return (x..y) > (y..x) end) |
|||
return numbers |
|||
end |
|||
for _,numbers in pairs({{1, 34, 3, 98, 9, 76, 45, 4}, {54, 546, 548, 60}}) do |
|||
print(('Numbers: {%s}\n Largest integer: %s'):format( |
|||
table.concat(numbers,","),table.concat(icsort(numbers)) |
|||
)) |
|||
end</lang> |
|||
{{out}} |
|||
<pre>Numbers: {1,34,3,98,9,76,45,4} |
|||
Largest integer: 998764543431 |
|||
Numbers: {54,546,548,60} |
|||
Largest integer: 6054854654</pre> |
|||
=={{header|Mathematica}}== |
|||
<lang Mathematica>makeLargestInt[list_] := Module[{sortedlist}, |
|||
sortedlist = Sort[list, Order[ToString[#1] <> ToString[#2], ToString[#2] <> ToString[#1]] < 0 &]; |
|||
Map[ToString, sortedlist] // StringJoin // FromDigits |
|||
] |
|||
(* testing with two examples *) |
|||
makeLargestInt[{1, 34, 3, 98, 9, 76, 45, 4}] |
|||
makeLargestInt[{54, 546, 548, 60}]</lang> |
|||
{{out}} |
|||
<pre>998764543431 |
|||
6054854654</pre> |
|||
=={{header|min}}== |
|||
{{works with|min|0.19.6}} |
|||
<lang min>(quote cons "" join) :s+ |
|||
('string map (over over swap s+ 's+ dip <) sort "" join int) :fn |
|||
(1 34 3 98 9 76 45 4) fn puts! |
|||
(54 546 548 60) fn puts!</lang> |
|||
{{out}} |
|||
<pre> |
|||
998764543431 |
|||
6054854654 |
|||
</pre> |
|||
=={{header|NetRexx}}== |
|||
<lang NetRexx>/* NetRexx */ |
|||
options replace format comments java crossref symbols nobinary |
|||
runSample(arg) |
|||
return |
|||
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
|||
method largestInt(il) public static |
|||
ri = '' |
|||
wa = '' |
|||
-- put the list into an indexed string |
|||
wa[0] = il.words |
|||
loop ww = 1 to wa[0] |
|||
wa[ww] = il.word(ww) |
|||
end ww |
|||
-- order the list |
|||
loop wx = 1 to wa[0] - 1 |
|||
loop wy = wx + 1 to wa[0] |
|||
xx = wa[wx] |
|||
yy = wa[wy] |
|||
xy = xx || yy |
|||
yx = yy || xx |
|||
if xy < yx then do |
|||
-- swap xx and yy |
|||
wa[wx] = yy |
|||
wa[wy] = xx |
|||
end |
|||
end wy |
|||
end wx |
|||
-- rebuild list from indexed string |
|||
loop ww = 1 to wa[0] |
|||
ri = ri wa[ww] |
|||
end ww |
|||
return ri.space(0) -- concatenate the list elements into a single numeric |
|||
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
|||
method runSample(arg) private static |
|||
ints = [ - |
|||
'1 34 3 98 9 76 45 4', - |
|||
'54 546 548 60' - |
|||
] |
] |
||
loop il over ints |
|||
say largestInt(il).right(20) ':' il.space(1, ',') |
|||
end il |
|||
return |
|||
</lang> |
|||
{{out}} |
|||
<pre> |
|||
998764543431 : 1,34,3,98,9,76,45,4 |
|||
6054854654 : 54,546,548,60 |
|||
</pre> |
|||
=={{header|Nim}}== |
|||
<lang nim>import algorithm, sequtils, strutils, sugar |
|||
proc maxNum(x: seq[int]): string = |
|||
var c = x.mapIt($it) |
|||
c.sort((x, y) => cmp(y&x, x&y)) |
|||
c.join() |
|||
echo maxNum(@[1, 34, 3, 98, 9, 76, 45, 4]) |
|||
echo maxNum(@[54, 546, 548, 60])</lang> |
|||
{{out}} |
|||
<pre>998764543431 |
|||
6054854654</pre> |
|||
=={{header|OCaml}}== |
|||
<lang ocaml>let myCompare a b = compare (b ^ a) (a ^ b) |
|||
let icsort nums = String.concat "" (List.sort myCompare (List.map string_of_int nums))</lang> |
|||
;testing |
|||
<pre> |
|||
# icsort [1;34;3;98;9;76;45;4];; |
|||
- : string = "998764543431" |
|||
# icsort [54;546;548;60];; |
|||
- : string = "6054854654" |
|||
</pre> |
|||
=={{header|Oforth}}== |
|||
<lang Oforth>: largestInt map(#asString) sortWith(#[ 2dup + -rot swap + > ]) sum asInteger ;</lang> |
|||
{{out}} |
|||
<pre> |
|||
[ [1, 34, 3, 98, 9, 76, 45, 4], [54, 546, 548, 60] ] map(#largestInt) . |
|||
[998764543431, 6054854654] |
|||
</pre> |
|||
=={{header|PARI/GP}}== |
|||
Sorts then joins. Most of the noise comes from converting a vector of integers into a concatenated integer: <code>eval(concat(apply(n->Str(n),v)))</code>. Note that the short form <code>eval(concat(apply(Str,v)))</code> is not valid here because <code>Str</code> is variadic. |
|||
<lang parigp>large(v)=eval(concat(apply(n->Str(n),vecsort(v,(x,y)->eval(Str(y,x,"-",x,y)))))); |
|||
large([1, 34, 3, 98, 9, 76, 45, 4]) |
|||
large([54, 546, 548, 60])</lang> |
|||
{{out}} |
|||
<pre>%1 = 998764543431 |
|||
%2 = 6054854654</pre> |
|||
=={{header|Pascal}}== |
|||
tested with freepascal.Used a more extreme example 3. |
|||
===algorithm 3=== |
|||
<lang pascal>const |
|||
base = 10; |
|||
MaxDigitCnt = 11; |
|||
source1 : array[0..7] of integer = (1, 34, 3, 98, 9, 76, 45, 4); |
|||
source2 : array[0..3] of integer = (54,546,548,60); |
|||
source3 : array[0..3] of integer = (60, 54,545454546,0); |
|||
type |
|||
tdata = record |
|||
datOrg, |
|||
datMod : LongWord; |
|||
datStrOrg : string[MaxDigitCnt]; |
|||
end; |
|||
tArrData = array of tData; |
|||
procedure DigitCount(var n: tdata); |
|||
begin |
|||
with n do |
|||
//InttoStr is very fast |
|||
str(datOrg,datStrOrg); |
|||
end; |
|||
procedure InsertData(var n: tdata;data:LongWord); |
|||
begin |
|||
n.datOrg := data; |
|||
DigitCount(n); |
|||
end; |
|||
function FindMaxLen(const ArrData:tArrData): LongWord; |
|||
var |
|||
cnt : longInt; |
|||
res,t : LongWord; |
|||
begin |
|||
res := 0;// 1 is minimum |
|||
for cnt := High(ArrData) downto Low(ArrData) do |
|||
begin |
|||
t := length(ArrData[cnt].datStrOrg); |
|||
IF res < t then |
|||
res := t; |
|||
end; |
|||
FindMaxLen := res; |
|||
end; |
|||
procedure ExtendCount(var ArrData:tArrData;newLen: integer); |
|||
var |
|||
cnt, |
|||
i,k : integer; |
|||
begin |
|||
For cnt := High(ArrData) downto Low(ArrData) do |
|||
with ArrData[cnt] do |
|||
begin |
|||
datMod := datOrg; |
|||
i := newlen-length(datStrOrg); |
|||
k := 1; |
|||
while i > 0 do |
|||
begin |
|||
datMod := datMod *Base+Ord(datStrOrg[k])-Ord('0'); |
|||
inc(k); |
|||
IF k >length(datStrOrg) then |
|||
k := 1; |
|||
dec(i); |
|||
end; |
|||
end; |
|||
end; |
|||
procedure SortArrData(var ArrData:tArrData); |
|||
var |
|||
i, |
|||
j,idx : integer; |
|||
tmpData : tData; |
|||
begin |
|||
For i := High(ArrData) downto Low(ArrData)+1 do |
|||
begin |
|||
idx := i; |
|||
j := i-1; |
|||
For j := j downto Low(ArrData) do |
|||
IF ArrData[idx].datMod < ArrData[j].datMod then |
|||
idx := j; |
|||
IF idx <> i then |
|||
begin |
|||
tmpData := ArrData[idx]; |
|||
ArrData[idx]:= ArrData[i]; |
|||
ArrData[i] := tmpData; |
|||
end; |
|||
end; |
|||
end; |
|||
procedure ArrDataOutput(const ArrData:tArrData); |
|||
var |
|||
i,l : integer; |
|||
s : string; |
|||
begin |
|||
{ the easy way |
|||
For i := High(ArrData) downto Low(ArrData) do |
|||
write(ArrData[i].datStrOrg); |
|||
writeln; |
|||
*} |
|||
l := 0; |
|||
For i := High(ArrData) downto Low(ArrData) do |
|||
inc(l,length(ArrData[i].datStrOrg)); |
|||
setlength(s,l); |
|||
l:= 1; |
|||
For i := High(ArrData) downto Low(ArrData) do |
|||
with ArrData[i] do |
|||
begin |
|||
move(datStrOrg[1],s[l],length(datStrOrg)); |
|||
inc(l,length(datStrOrg)); |
|||
end; |
|||
writeln(s); |
|||
end; |
|||
procedure HighestInt(var ArrData:tArrData); |
|||
begin |
|||
ExtendCount(ArrData,FindMaxLen(ArrData)); |
|||
SortArrData(ArrData); |
|||
ArrDataOutput(ArrData); |
|||
end; |
|||
var |
|||
i : integer; |
|||
tmpData : tArrData; |
|||
begin |
|||
// Source1 |
|||
setlength(tmpData,length(source1)); |
|||
For i := low(tmpData) to high(tmpData) do |
|||
InsertData(tmpData[i],source1[i]); |
|||
HighestInt(tmpData); |
|||
// Source2 |
|||
setlength(tmpData,length(source2)); |
|||
For i := low(tmpData) to high(tmpData) do |
|||
InsertData(tmpData[i],source2[i]); |
|||
HighestInt(tmpData); |
|||
// Source3 |
|||
setlength(tmpData,length(source3)); |
|||
For i := low(tmpData) to high(tmpData) do |
|||
InsertData(tmpData[i],source3[i]); |
|||
HighestInt(tmpData); |
|||
end.</lang> |
|||
{{out}} |
|||
<pre>998764543431 |
|||
6054854654 |
|||
60545454546540</pre> |
|||
====Inspired by Haskell ==== |
|||
generate the repetition by dividing /(10^CountDigits-1) |
|||
http://rosettacode.org/wiki/Largest_int_from_concatenated_ints#Compare_repeated_string_method |
|||
<lang pascal>const |
|||
base = 10; |
|||
MaxDigitCnt = 11; |
|||
source1 : array[0..7] of LongInt = (10 , 34, 3, 98, 9, 76, 45, 4); |
|||
source2 : array[0..3] of LongInt = (54,546,548,60); |
|||
source3 : array[0..3] of LongInt = (0,2121212122,21,60); |
|||
type |
|||
tdata = record |
|||
datMod : double; |
|||
datOrg : LongInt; |
|||
//InttoStr is very fast and the string is always needed |
|||
datStrOrg : string[MaxDigitCnt]; |
|||
end; |
|||
tArrData = array of tData; |
|||
procedure InsertData(var n: tdata;data:LongWord); |
|||
begin |
|||
with n do |
|||
begin |
|||
datOrg := data; |
|||
str(datOrg,datStrOrg); |
|||
end; |
|||
end; |
|||
function FindMaxLen(const ArrData:tArrData): LongWord; |
|||
var |
|||
cnt : longInt; |
|||
res,t : LongWord; |
|||
begin |
|||
res := 0;// 1 is minimum |
|||
for cnt := High(ArrData) downto Low(ArrData) do |
|||
begin |
|||
t := length(ArrData[cnt].datStrOrg); |
|||
IF res < t then |
|||
res := t; |
|||
end; |
|||
FindMaxLen := res; |
|||
end; |
|||
procedure ExtendData(var ArrData:tArrData;newLen: integer); |
|||
var |
|||
cnt, |
|||
i : integer; |
|||
begin |
|||
For cnt := High(ArrData) downto Low(ArrData) do |
|||
with ArrData[cnt] do |
|||
begin |
|||
//generating 10^length(datStrOrg) |
|||
datMod := 1; |
|||
i := length(datStrOrg); |
|||
// i always >= 1 |
|||
repeat |
|||
datMod := base*datMod; |
|||
dec(i); |
|||
until i <= 0; |
|||
// 1/(datMod-1.0) = 1/(9...9) |
|||
datMod := datOrg/(datMod-1.0)+datOrg; |
|||
i := newlen-length(datStrOrg); |
|||
For i := i downto 1 do |
|||
datMod := datMod*Base; |
|||
end; |
|||
end; |
|||
procedure SortArrData(var ArrData:tArrData); |
|||
//selection sort |
|||
var |
|||
i, |
|||
j,idx : integer; |
|||
tmpData : tData; |
|||
begin |
|||
For i := High(ArrData) downto Low(ArrData)+1 do |
|||
begin |
|||
idx := i; |
|||
j := i-1; |
|||
//select max |
|||
For j := j downto Low(ArrData) do |
|||
IF ArrData[idx].datMod < ArrData[j].datMod then |
|||
idx := j; |
|||
//finally swap |
|||
IF idx <> i then |
|||
begin |
|||
tmpData := ArrData[idx]; |
|||
ArrData[idx]:= ArrData[i]; |
|||
ArrData[i] := tmpData; |
|||
end; |
|||
end; |
|||
end; |
|||
procedure ArrDataOutput(const ArrData:tArrData); |
|||
var |
|||
i : integer; |
|||
begin |
|||
{ the easy way} |
|||
For i := High(ArrData) downto Low(ArrData) do |
|||
write(ArrData[i].datStrOrg); |
|||
writeln; |
|||
end; |
|||
procedure HighestInt(var ArrData:tArrData); |
|||
begin |
|||
ExtendData(ArrData,FindMaxLen(ArrData)); |
|||
SortArrData(ArrData); |
|||
ArrDataOutput(ArrData); |
|||
end; |
|||
var |
|||
i : integer; |
|||
tmpData : tArrData; |
|||
begin |
|||
// Source1 |
|||
setlength(tmpData,length(source1)); |
|||
For i := low(tmpData) to high(tmpData) do |
|||
InsertData(tmpData[i],source1[i]); |
|||
HighestInt(tmpData); |
|||
// Source2 |
|||
setlength(tmpData,length(source2)); |
|||
For i := low(tmpData) to high(tmpData) do |
|||
InsertData(tmpData[i],source2[i]); |
|||
HighestInt(tmpData); |
|||
// Source3 |
|||
setlength(tmpData,length(source3)); |
|||
For i := low(tmpData) to high(tmpData) do |
|||
InsertData(tmpData[i],source3[i]); |
|||
HighestInt(tmpData); |
|||
end.</lang> |
|||
{{out}} |
|||
<pre>9987645434310 |
|||
6054854654 |
|||
602121212122210></pre> |
|||
=={{header|Perl}}== |
|||
<lang perl>sub maxnum { |
|||
join '', sort { "$b$a" cmp "$a$b" } @_ |
|||
} |
|||
print maxnum(1, 34, 3, 98, 9, 76, 45, 4), "\n"; |
|||
print maxnum(54, 546, 548, 60), "\n";</lang> |
|||
{{out}} |
|||
<pre>998764543431 |
|||
6054854654</pre> |
|||
=={{header|Phix}}== |
|||
<lang Phix>function catcmp(string a, string b) |
|||
return compare(b&a,a&b) |
|||
end function |
|||
function method2(sequence s) |
|||
for i=1 to length(s) do |
|||
s[i] = sprintf("%d",s[i]) |
|||
end for |
|||
s = custom_sort(routine_id("catcmp"),s) |
|||
return join(s,"") |
|||
end function |
|||
? method2({1,34,3,98,9,76,45,4}) |
|||
? method2({54,546,548,60})</lang> |
|||
{{out}} |
|||
<pre> |
|||
"998764543431" |
|||
"6054854654" |
|||
</pre> |
|||
=={{header|PHP}}== |
|||
<lang php>function maxnum($nums) { |
|||
usort($nums, function ($x, $y) { return strcmp("$y$x", "$x$y"); }); |
|||
return implode('', $nums); |
|||
} |
|||
echo maxnum(array(1, 34, 3, 98, 9, 76, 45, 4)), "\n"; |
|||
echo maxnum(array(54, 546, 548, 60)), "\n";</lang> |
|||
{{out}} |
|||
<pre>998764543431 |
|||
6054854654</pre> |
|||
=={{header|PicoLisp}}== |
|||
Here are solutions for all three algorithms. |
|||
The third solution actually avoids padding the numbers, by converting them into |
|||
circular lists and comparing these. As a drawback, however, this works only for |
|||
unique lists (as the comparison of identical numbers would not terminate), so a |
|||
better solution might involve additional checks. |
|||
<lang PicoLisp>(load "@lib/simul.l") # For 'permute'</lang> |
|||
===Algorithm 1=== |
|||
<lang PicoLisp>(for L '((1 34 3 98 9 76 45 4) (54 546 548 60)) |
|||
(prinl (maxi format (permute L))) )</lang> |
|||
===Algorithm 2=== |
|||
<lang PicoLisp>(for L '((1 34 3 98 9 76 45 4) (54 546 548 60)) |
|||
(prinl |
|||
(sort L |
|||
'((A B) |
|||
(> |
|||
(format (pack A B)) |
|||
(format (pack B A)) ) ) ) ) )</lang> |
|||
===Algorithm 3=== |
|||
<lang PicoLisp>(for L '((1 34 3 98 9 76 45 4) (54 546 548 60)) |
|||
(prinl |
|||
(flip |
|||
(by '((N) (apply circ (chop N))) sort L) ) ) )</lang> |
|||
{{out}} in all three cases: |
|||
<pre>998764543431 |
|||
6054854654</pre> |
|||
=={{header|PL/I}}== |
|||
<lang pli> |
|||
/* Largest catenation of integers 16 October 2013 */ |
|||
/* Sort using method 2, comparing pairs of adjacent integers. */ |
|||
Largest: procedure options (main); |
|||
declare s(*) char (20) varying controlled, n fixed binary; |
|||
get (n); |
|||
allocate s(n); |
|||
get list (s); |
|||
s = trim(s); |
|||
put skip edit (s) (a, x(1)); |
|||
put skip list ('Largest integer=', Largest_integer()); |
|||
largest_integer: procedure () returns (char(100) varying); |
|||
declare sorted bit (1); |
|||
declare (true value ('1'b), false value ('0'b)) bit (1); |
|||
declare i fixed binary; |
|||
declare temp character(20) varying; |
|||
do until (sorted); |
|||
sorted = true; |
|||
do i = 1 to n-1; |
|||
if char(s(i)) || char(s(i+1)) < char(s(i+1)) || char(s(i)) then |
|||
do; |
|||
temp = s(i); s(i) = s(i+1); s(i+1) = temp; sorted = false; |
|||
end; |
|||
end; |
|||
end; |
|||
return (string(s)); |
|||
end largest_integer; |
|||
end Largest; |
|||
</lang> |
|||
<pre> |
|||
54 546 548 60 |
|||
Largest integer= 6054854654 |
|||
1 34 3 98 9 76 45 4 |
|||
Largest integer= 998764543431 |
|||
</pre> |
|||
=={{header|PowerShell}}== |
|||
{{works with|PowerShell|2}} |
|||
Using algorithm 3 |
|||
<lang PowerShell>Function Get-LargestConcatenation ( [int[]]$Integers ) |
|||
{ |
|||
# Get the length of the largest integer |
|||
$Length = ( $Integers | Sort -Descending | Select -First 1 ).ToString().Length |
|||
# Convert to an array of strings, |
|||
# sort by each number repeated Length times and truncated to Length, |
|||
# and concatenate (join) |
|||
$Concat = ( [string[]]$Integers | Sort { ( $_ * $Length ).Substring( 0, $Length ) } -Descending ) -join '' |
|||
# Convert to integer (upsizing type if needed) |
|||
try { $Integer = [ int32]$Concat } |
|||
catch { try { $Integer = [ int64]$Concat } |
|||
catch { $Integer = [bigint]$Concat } } |
|||
return $Integer |
|||
}</lang> |
|||
<lang PowerShell>Get-LargestConcatenation 1, 34, 3, 98, 9, 76, 45, 4 |
|||
Get-LargestConcatenation 54, 546, 548, 60 |
|||
Get-LargestConcatenation 54, 546, 548, 60, 54, 546, 548, 60</lang> |
|||
{{out}} |
|||
<pre>998764543431 |
|||
6054854654 |
|||
60605485485465465454</pre> |
|||
=={{header|Prolog}}== |
|||
Works with SWI-Prolog 6.5.3. |
|||
===All permutations method=== |
|||
<lang Prolog>largest_int_v1(In, Out) :- |
|||
maplist(name, In, LC), |
|||
aggregate(max(V), get_int(LC, V), Out). |
|||
get_int(LC, V) :- |
|||
permutation(LC, P), |
|||
append(P, LV), |
|||
name(V, LV). |
|||
</lang> |
|||
{{out}} |
|||
<pre> ?- largest_int_v1([1, 34, 3, 98, 9, 76, 45, 4], Out). |
|||
Out = 998764543431. |
|||
?- largest_int_v1([54, 546, 548, 60], Out). |
|||
Out = 6054854654. |
|||
</pre> |
|||
===Method 2=== |
|||
<lang Prolog>largest_int_v2(In, Out) :- |
|||
maplist(name, In, LC), |
|||
predsort(my_sort,LC, LCS), |
|||
append(LCS, LC1), |
|||
name(Out, LC1). |
|||
my_sort(R, L1, L2) :- |
|||
append(L1, L2, V1), name(I1, V1), |
|||
append(L2, L1, V2), name(I2, V2), |
|||
( I1 < I2, R = >; I1 = I2, R = '='; R = <). |
|||
% particular case 95 958 |
|||
my_sort(>, [H1], [H1, H2 | _]) :- |
|||
H1 > H2. |
|||
my_sort(<, [H1], [H1, H2 | _]) :- |
|||
H1 < H2. |
|||
my_sort(R, [H1], [H1, H1 | T]) :- |
|||
my_sort(R, [H1], [H1 | T]). |
|||
% particular case 958 95 |
|||
my_sort(>, [H1, H2 | _], [H1]) :- |
|||
H1 > H2. |
|||
my_sort(<, [H1, H2 | _], [H1]) :- |
|||
H1 < H2. |
|||
my_sort(R, [H1, H1 | T], [H1]) :- |
|||
my_sort(R, [H1 | T], [H1]) . |
|||
</lang> |
|||
{{out}} |
|||
<pre> ?- largest_int_v2([1, 34, 3, 98, 9, 76, 45, 4], Out). |
|||
Out = 998764543431 . |
|||
?- largest_int_v2([54, 546, 548, 60], Out). |
|||
Out = 5486054654 . |
|||
</pre> |
|||
=={{header|Python}}== |
|||
===Python: Sort on comparison of concatenated ints method=== |
|||
This also shows one of the few times where cmp= is better than key= on sorted() |
|||
<lang python>try: |
|||
cmp # Python 2 OK or NameError in Python 3 |
|||
def maxnum(x): |
|||
return ''.join(sorted((str(n) for n in x), |
|||
cmp=lambda x,y:cmp(y+x, x+y))) |
|||
except NameError: |
|||
# Python 3 |
|||
from functools import cmp_to_key |
|||
def cmp(x, y): |
|||
return -1 if x<y else ( 0 if x==y else 1) |
|||
def maxnum(x): |
|||
return ''.join(sorted((str(n) for n in x), |
|||
key=cmp_to_key(lambda x,y:cmp(y+x, x+y)))) |
|||
for numbers in [(1, 34, 3, 98, 9, 76, 45, 4), (54, 546, 548, 60): |
|||
print('Numbers: %r\n Largest integer: %15s' % (numbers, maxnum(numbers)))</lang> |
|||
{{out}} |
|||
<pre>Numbers: (1, 34, 3, 98, 9, 76, 45, 4) |
|||
Largest integer: 998764543431 |
|||
Numbers: (54, 546, 548, 60) |
|||
Largest integer: 6054854654</pre> |
|||
===Python: Compare repeated string method=== |
|||
<lang python>def maxnum(x): |
|||
maxlen = len(str(max(x))) |
|||
return ''.join(sorted((str(v) for v in x), reverse=True, |
|||
key=lambda i: i*(maxlen * 2 // len(i)))) |
|||
for numbers in [(212, 21221), (1, 34, 3, 98, 9, 76, 45, 4), (54, 546, 548, 60)]: |
|||
print('Numbers: %r\n Largest integer: %15s' % (numbers, maxnum(numbers)))</lang> |
|||
{{out}} |
|||
<pre>Numbers: (212, 21221) |
|||
Largest integer: 21221221 |
|||
Numbers: (1, 34, 3, 98, 9, 76, 45, 4) |
|||
Largest integer: 998764543431 |
|||
Numbers: (54, 546, 548, 60) |
|||
Largest integer: 6054854654</pre> |
|||
{{works with|Python|2.6+}} |
|||
<lang python>from fractions import Fraction |
|||
from math import log10 |
|||
def maxnum(x): |
|||
return ''.join(str(n) for n in sorted(x, reverse=True, |
|||
key=lambda i: Fraction(i, 10**(int(log10(i))+1)-1))) |
|||
for numbers in [(1, 34, 3, 98, 9, 76, 45, 4), (54, 546, 548, 60)]: |
|||
print('Numbers: %r\n Largest integer: %15s' % (numbers, maxnum(numbers)))</lang> |
|||
;Output as first Python example, above. |
|||
===Python: Try all permutations method=== |
|||
<lang python>from itertools import permutations |
|||
def maxnum(x): |
|||
return max(int(''.join(n) for n in permutations(str(i) for i in x))) |
|||
for numbers in [(1, 34, 3, 98, 9, 76, 45, 4), (54, 546, 548, 60)]: |
|||
print('Numbers: %r\n Largest integer: %15s' % (numbers, maxnum(numbers)))</lang> |
|||
;Output as above. |
|||
=={{header|Racket}}== |
|||
<lang Racket> |
|||
#lang racket |
|||
(define (largest-int ns) |
|||
(string->number (apply ~a (sort ns (λ(x y) (string>? (~a x y) (~a y x))))))) |
|||
(map largest-int '((1 34 3 98 9 76 45 4) (54 546 548 60))) |
|||
;; -> '(998764543431 6054854654) |
|||
</lang> |
|||
=={{header|Raku}}== |
|||
(formerly Perl 6) |
|||
<lang perl6>sub maxnum(*@x) { |
|||
[~] @x.sort: -> $a, $b { $b ~ $a leg $a ~ $b } |
|||
} |
|||
say maxnum <1 34 3 98 9 76 45 4>; |
|||
say maxnum <54 546 548 60>;</lang> |
|||
{{out}} |
|||
<pre>998764543431 |
|||
6054854654</pre> |
|||
=={{header|Red}}== |
|||
<lang Rebol>Red [] |
|||
foreach seq [[1 34 3 98 9 76 45 4] [54 546 548 60]] [ |
|||
print rejoin sort/compare seq function [a b] [ (rejoin [a b]) > rejoin [b a] ] |
|||
] |
|||
</lang> |
|||
{{out}} |
|||
<pre> |
|||
998764543431 |
|||
6054854654</pre> |
|||
=={{header|REXX}}== |
|||
The algorithm used is based on exact comparisons (left to right) with ''right digit fill'' of the ''left digit''. |
|||
<br>This allows the integers to be of any size. |
|||
This REXX version works with any size integer (negative, zero, positive), and does some basic error checking to |
|||
<br>verify that the numbers are indeed integers (and it also normalizes the integers). |
|||
The absolute value is used for negative numbers. No sorting of the numbers is required for the 1<sup>st</sup> two examples. |
|||
===simple integers=== |
|||
<lang rexx>/*REXX program constructs the largest integer from an integer list using concatenation.*/ |
|||
@.=.; @.1 = 1 34 3 98 9 76 45 4 /*the 1st integer list to be used. */ |
|||
@.2 = 54 546 548 60 /* " 2nd " " " " " */ |
|||
@.3 = 4 45 54 5 /* " 3rd " " " " " */ |
|||
w=0 /* [↓] process all the integer lists.*/ |
|||
do j=1 while @.j\==.; z= space(@.j) /*keep truckin' until lists exhausted. */ |
|||
w=max(w, length(z) ); $= /*obtain maximum width to align output.*/ |
|||
do while z\=''; idx= 1; big= norm(1) /*keep examining the list until done.*/ |
|||
do k=2 to words(z); #= norm(k) /*obtain an a number from the list. */ |
|||
L= max(length(big), length(#) ) /*get the maximum length of the integer*/ |
|||
if left(#, L, left(#, 1) ) <<= left(big, L, left(big, 1) ) then iterate |
|||
big= #; idx= k /*we found a new biggie (and the index)*/ |
|||
end /*k*/ /* [↑] find max concatenated integer. */ |
|||
z= delword(z, idx, 1) /*delete this maximum integer from list*/ |
|||
$= $ || big /*append " " " ───► $. */ |
|||
end /*while z*/ /* [↑] process all integers in a list.*/ |
|||
say 'largest concatenatated integer from ' left( space(@.j), w) " is ─────► " $ |
|||
end /*j*/ /* [↑] process each list of integers. */ |
|||
exit 0 /*stick a fork in it, we're all done. */ |
|||
/*──────────────────────────────────────────────────────────────────────────────────────*/ |
|||
norm: arg i; #= word(z, i); er= '***error***'; if left(#, 1)=="-" then #= substr(#, 2) |
|||
if \datatype(#,'W') then do; say er # "isn't an integer."; exit 13; end; return #/1</lang> |
|||
{{out|output|text= when using the default (internal) integer lists:}} |
|||
<pre> |
|||
largest concatenatated integer from 1 34 3 98 9 76 45 4 is ─────► 998764543431 |
|||
largest concatenatated integer from 54 546 548 60 is ─────► 6054854654 |
|||
largest concatenatated integer from 4 45 54 5 is ─────► 554454 |
|||
</pre> |
|||
===exponentiated integers=== |
|||
In REXX, a number such as '''6.6e77''' would be considered an integer ''if'' the (current) '''numeric digits''' is |
|||
<br>large enough to express that number as an integer without the exponent. |
|||
The default for REXX is '''9''' decimal digits, but the '''norm''' function automatically uses enough decimal digits to |
|||
<br>express the number as an integer. |
|||
This REXX version can handle any sized integer (most REXXes can handle up to around eight million decimal |
|||
<br>digits, but displaying the result would be problematic for results wider than the display area). |
|||
<lang rexx>/*REXX program constructs the largest integer from an integer list using concatenation.*/ |
|||
@.=.; @.1 = 1 34 3 98 9 76 45 4 /*the 1st integer list to be used. */ |
|||
@.2 = 54 546 548 60 /* " 2nd " " " " " */ |
|||
@.3 = 4 45 54 5 /* " 3rd " " " " " */ |
|||
@.4 = 4 45 54 5 6.6e77 /* " 4th " " " " " */ |
|||
w= 0 /* [↓] process all the integer lists.*/ |
|||
do j=1 while @.j\==.; z= space(@.j) /*keep truckin' until lists exhausted. */ |
|||
w=max(w, length(z) ); $= /*obtain maximum width to align output.*/ |
|||
do while z\=''; idx=1; big= norm(1) /*keep examining the list until done.*/ |
|||
do k=2 to words(z); #= norm(k) /*obtain an a number from the list. */ |
|||
L= max(length(big), length(#) ) /*get the maximum length of the integer*/ |
|||
if left(#, L, left(#, 1) ) <<= left(big, L, left(big, 1) ) then iterate |
|||
big=#; idx= k /*we found a new biggie (and the index)*/ |
|||
end /*k*/ /* [↑] find max concatenated integer. */ |
|||
z= delword(z, idx, 1) /*delete this maximum integer from list*/ |
|||
$= $ || big /*append " " " ───► $. */ |
|||
end /*while z*/ /* [↑] process all integers in a list.*/ |
|||
say 'largest concatenatated integer from ' left( space(@.j), w) " is " $ |
|||
end /*j*/ /* [↑] process each list of integers. */ |
|||
exit /*stick a fork in it, we're all done. */ |
|||
/*──────────────────────────────────────────────────────────────────────────────────────*/ |
|||
norm: arg i; #= word(z, i); er= '***error***'; if left(#, 1)=="-" then #= substr(#, 2) |
|||
if \datatype(#, 'N') then signal er13 /*go and tell err msg.*/ |
|||
else #= # / 1 /*a #, so normalize it*/ |
|||
if pos('E',#)>0 then do; parse var # mant "E" pow /*Has exponent? Expand*/ |
|||
numeric digits pow + length(mand) /*expand digs, adjust#*/ |
|||
end |
|||
if datatype(#, 'W') then return # / 1 |
|||
er13: say er # "isn't an integer."; exit 13</lang> |
|||
{{out|output|text= when using the default (internal) integer lists:}} |
|||
(Output shown at three-quarter size.) |
|||
<pre style="font-size:75%"> |
|||
largest concatenatated integer from 1 34 3 98 9 76 45 4 is 998764543431 |
|||
largest concatenatated integer from 54 546 548 60 is 6054854654 |
|||
largest concatenatated integer from 4 45 54 5 is 554454 |
|||
largest concatenatated integer from 4 45 54 5 6.6e77 is 660000000000000000000000000000000000000000000000000000000000000000000000000000554454 |
|||
</pre> |
|||
===Alternate Version=== |
|||
Inspired by the previous versions. |
|||
<lang>/*REXX program constructs the largest integer from an integer list using concatenation.*/ |
|||
l.=''; l.1 = '1 34 3 98 9 76 45 4' /*the 1st integer list to be used. */ |
|||
l.2 = '54 546 548 60' /* " 2nd " " " " " */ |
|||
l.3 = ' 4 45 54 5' /* " 3rd " " " " " */ |
|||
l.4 = ' 4 45 54 5 6.6e77' /* " 4th " " " " " */ |
|||
l.5 = ' 3 3 .2' /* " 5th " " " " " */ |
|||
/* |
|||
soll.1=998764543431 |
|||
soll.2=6054854654 |
|||
soll.3=554454 |
|||
soll.4=660000000000000000000000000000000000000000000000000000000000000000000000000000545454 |
|||
*/ |
|||
l_length=0 |
|||
Do li=1 By 1 While l.li<>'' |
|||
l_length=max(l_length,length(space(l.li))) |
|||
End |
|||
Do li=1 By 1 While l.li<>'' |
|||
z='' |
|||
Do j=1 To words(l.li) |
|||
int=integer(word(l.li,j)) |
|||
If int='?' Then Do |
|||
Say left(space(l.li),l_length) '-> ** invalid ** bad integer' word(l.li,j) |
|||
Iterate li |
|||
End |
|||
Else |
|||
z=z int |
|||
End |
|||
/*Say copies(' ',l_length) ' ' soll.li */ |
|||
Say left(space(l.li),l_length) '->' largeint(l.li) |
|||
End |
|||
Exit |
|||
integer: Procedure |
|||
Numeric Digits 1000 |
|||
Parse Arg z |
|||
If Datatype(z,'W') Then |
|||
Return z+0 |
|||
Else |
|||
Return '?' |
|||
largeint: |
|||
result='' |
|||
Do While z<>'' /* [?] check the rest of the integers.*/ |
|||
big=word(z,1); index=1; LB=length(big) /*assume that first integer is biggest.*/ |
|||
do k=2 to words(z); |
|||
n=word(z,k) /*obtain an integer from the list. */ |
|||
L=max(LB,length(n)) /*get the maximum length of the integer*/ |
|||
if left(n,L,left(n,1))<<=left(big,L,left(big,1)) then iterate |
|||
big=n; index=k /*we found a new biggie (and the index)*/ |
|||
LB=length(big) |
|||
End /*k*/ |
|||
z=delword(z,index,1) /*delete this maximum integer from list*/ |
|||
result=result||big /*append " " " ---? $. */ |
|||
end /*while z*/ /* [?] process all integers in a list.*/ |
|||
Return result</lang> |
|||
{{out}} |
|||
<pre>1 34 3 98 9 76 45 4 -> 998764543431 |
|||
54 546 548 60 -> 6054854654 |
|||
4 45 54 5 -> 554454 |
|||
4 45 54 5 6.6e77 -> 660000000000000000000000000000000000000000000000000000000000000000000000000000554454 |
|||
3 3 .2 -> ** invalid ** bad integer .2</pre> |
|||
===Version 4=== |
|||
{{trans|NetRexx}} |
|||
<lang rexx>/*REXX program constructs the largest integer from an integer list using concatenation.*/ |
|||
l.=''; l.1 = '1 34 3 98 9 76 45 4' /*the 1st integer list to be used. */ |
|||
l.2 = '54 546 548 60' /* " 2nd " " " " " */ |
|||
l.3 = ' 4 45 54 5' /* " 3rd " " " " " */ |
|||
l.4 = ' 4 45 54 5 6.6e77' /* " 4th " " " " " */ |
|||
l.5 = ' 3 3 .2' /* " 5th " " " " " */ |
|||
l.6 = ' 4 45 54 5 6.6e1001' /* " 6th " " " " " */ |
|||
l.7 = ' 4.0000 45 54 5.00' /* " 7th " " " " " */ |
|||
l.8 = ' 10e999999999 5' /* " 8th " " " " " */ |
|||
l_length=0 |
|||
Do li=1 By 1 While l.li<>'' |
|||
l_length=max(l_length,length(space(l.li))) |
|||
End |
|||
Do li=1 By 1 While l.li<>'' |
|||
z='' |
|||
msg='' |
|||
Do j=1 To words(l.li) |
|||
int=integer(word(l.li,j)) |
|||
If int='?' Then Do |
|||
Say left(space(l.li),l_length) '-> ** invalid ** bad list item:' word(l.li,j) msg |
|||
Iterate li |
|||
End |
|||
Else |
|||
z=z int |
|||
End |
|||
zz=largeint(z) |
|||
If length(zz)<60 Then |
|||
Say left(space(l.li),l_length) '->' zz |
|||
Else |
|||
Say left(space(l.li),l_length) '->' left(zz,5)'...'right(zz,5) |
|||
End |
|||
Exit |
|||
integer: Procedure Expose msg |
|||
Numeric Digits 1000 |
|||
Parse Arg z |
|||
If Datatype(z,'W') Then |
|||
Return z/1 |
|||
Else Do |
|||
If Datatype(z,'NUM') Then Do |
|||
Do i=1 To 6 Until dig>=999999999 |
|||
dig= digits()*10 |
|||
dig=min(dig,999999999) |
|||
Numeric Digits dig |
|||
If Datatype(z,'W') Then |
|||
Return z/1 |
|||
End |
|||
msg='cannot convert it to an integer' |
|||
Return '?' |
|||
End |
|||
Else Do |
|||
msg='not a number (larger than what this REXX can handle)' |
|||
Return '?' |
|||
End |
|||
End |
|||
largeint: Procedure |
|||
Parse Arg list |
|||
w.0=words(list) |
|||
Do i=1 To w.0 |
|||
w.i=word(list,i) |
|||
End |
|||
Do wx=1 To w.0-1 |
|||
Do wy=wx+1 To w.0 |
|||
xx=w.wx |
|||
yy=w.wy |
|||
xy=xx||yy |
|||
yx=yy||xx |
|||
if xy < yx then do |
|||
/* swap xx and yy */ |
|||
w.wx = yy |
|||
w.wy = xx |
|||
end |
|||
End |
|||
End |
|||
list='' |
|||
Do ww=1 To w.0 |
|||
list=list w.ww |
|||
End |
|||
Return space(list,0)</lang> |
|||
{{out}} |
|||
<pre>1 34 3 98 9 76 45 4 -> 998764543431 |
|||
54 546 548 60 -> 6054854654 |
|||
4 45 54 5 -> 554454 |
|||
4 45 54 5 6.6e77 -> 66000...54454 |
|||
3 3 .2 -> ** invalid ** bad list item: .2 cannot convert it to an integer |
|||
4 45 54 5 6.6e1001 -> 66000...54454 |
|||
4.0000 45 54 5.00 -> 554454 |
|||
10e999999999 5 -> ** invalid ** bad list item: 10e999999999 not a number (larger than what this REXX can handle)</pre> |
|||
=={{header|Ring}}== |
|||
<lang ring> |
|||
nums=[1,34,3,98,9,76,45,4] |
|||
see largestInt(8) + nl |
|||
nums=[54,546,548,60] |
|||
see largestInt(4) + nl |
|||
func largestInt len |
|||
l = "" |
|||
sorted = false |
|||
while not sorted |
|||
sorted=true |
|||
for i=1 to len-1 |
|||
a=string(nums[i]) |
|||
b=string(nums[i+1]) |
|||
if a+b<b+a |
|||
temp = nums[i] |
|||
nums[i] = nums[i+1] |
|||
nums[i+1] = temp |
|||
sorted=false ok |
|||
next |
|||
end |
|||
for i=1 to len |
|||
l+=string(nums[i]) |
|||
next |
|||
return l |
|||
</lang> |
|||
Output: |
|||
<pre> |
|||
998764543431 |
|||
6054854654 |
|||
</pre> |
|||
=={{header|Ruby}}== |
|||
===Sort on comparison of concatenated ints method=== |
|||
{{trans|Tcl}} |
|||
<lang Ruby>def icsort nums |
|||
nums.sort { |x, y| "#{y}#{x}" <=> "#{x}#{y}" } |
|||
end |
|||
[[54, 546, 548, 60], [1, 34, 3, 98, 9, 76, 45, 4]].each do |c| |
|||
p c # prints nicer in Ruby 1.8 |
|||
puts icsort(c).join |
|||
end</lang> |
|||
{{out}} |
|||
<pre>[54, 546, 548, 60] |
|||
6054854654 |
|||
[1, 34, 3, 98, 9, 76, 45, 4] |
|||
998764543431</pre> |
|||
===Compare repeated string method=== |
|||
<lang ruby>def icsort nums |
|||
maxlen = nums.max.to_s.length |
|||
nums.map{ |x| x.to_s }.sort_by { |x| x * (maxlen * 2 / x.length) }.reverse |
|||
end |
|||
[[54, 546, 548, 60], [1, 34, 3, 98, 9, 76, 45, 4]].each do |c| |
|||
p c # prints nicer in Ruby 1.8 |
|||
puts icsort(c).join |
|||
end</lang> |
|||
;Output as above. |
|||
<lang ruby>require 'rational' #Only needed in Ruby < 1.9 |
|||
def icsort nums |
|||
nums.sort_by { |i| Rational(i, 10**(Math.log10(i).to_i+1)-1) }.reverse |
|||
end |
|||
[[54, 546, 548, 60], [1, 34, 3, 98, 9, 76, 45, 4]].each do |c| |
|||
p c # prints nicer in Ruby 1.8 |
|||
puts icsort(c).join |
|||
end</lang> |
|||
;Output as above. |
|||
=={{header|Run BASIC}}== |
|||
<lang runbasic>a1$ = "1, 34, 3, 98, 9, 76, 45, 4" |
|||
a2$ = "54,546,548,60" |
|||
print "Max Num ";a1$;" = ";maxNum$(a1$) |
|||
print "Max Num ";a2$;" = ";maxNum$(a2$) |
|||
function maxNum$(a1$) |
|||
while word$(a1$,i+1,",") <> "" |
|||
i = i + 1 |
|||
a$(i) = trim$(word$(a1$,i,",")) |
|||
wend |
|||
s = 1 |
|||
while s = 1 |
|||
s = 0 |
|||
for j = 1 to i -1 |
|||
if a$(j)+a$(j+1) < a$(j+1)+a$(j) then |
|||
h$ = a$(j) |
|||
a$(j) = a$(j+1) |
|||
a$(j+1) = h$ |
|||
s = 1 |
|||
end if |
|||
next j |
|||
wend |
|||
for j = 1 to i |
|||
maxNum$ = maxNum$ ; a$(j) |
|||
next j |
|||
end function</lang> |
|||
{{out}} |
|||
<pre>Max Num 1, 34, 3, 98, 9, 76, 45, 4 = 998764543431 |
|||
Max Num 54,546,548,60 = 6054854654</pre> |
|||
=={{header|Rust}}== |
|||
<lang Rust>fn maxcat(a: &mut [u32]) { |
|||
a.sort_by(|x, y| { |
|||
let xy = format!("{}{}", x, y); |
|||
let yx = format!("{}{}", y, x); |
|||
xy.cmp(&yx).reverse() |
|||
}); |
|||
for x in a { |
|||
print!("{}", x); |
|||
} |
|||
println!(); |
|||
} |
|||
fn main() { |
|||
maxcat(&mut [1, 34, 3, 98, 9, 76, 45, 4]); |
|||
maxcat(&mut [54, 546, 548, 60]); |
|||
}</lang> |
|||
{{out}} |
|||
<pre>998764543431 |
|||
6054854654</pre> |
|||
=={{header|S-lang}}== |
|||
<lang S-lang>define catcmp(a, b) |
|||
{ |
|||
a = string(a); |
|||
b = string(b); |
|||
return strcmp(b+a, a+b); |
|||
} |
|||
define maxcat(arr) |
|||
{ |
|||
arr = arr[array_sort(arr, &catcmp)]; |
|||
variable result = "", elem; |
|||
foreach elem (arr) |
|||
result += string(elem); |
|||
return result; |
|||
} |
|||
print("max of series 1 is " + maxcat([1, 34, 3, 98, 9, 76, 45, 4])); |
|||
print("max of series 2 is " + maxcat([54, 546, 548, 60])); |
|||
</lang> |
|||
{{out}} |
|||
<pre>"max of series 1 is 998764543431" |
|||
"max of series 2 is 6054854654" |
|||
</pre> |
|||
=={{header|Scala}}== |
|||
{{libheader|Scala}} |
|||
<lang Scala>object LIFCI extends App { |
|||
def lifci(list: List[Long]) = list.permutations.map(_.mkString).max |
|||
println(lifci(List(1, 34, 3, 98, 9, 76, 45, 4))) |
|||
println(lifci(List(54, 546, 548, 60))) |
|||
}</lang> |
|||
{{out}} |
|||
<pre> |
|||
998764543431 |
|||
6054854654 |
|||
</pre> |
|||
=={{header|Scheme}}== |
|||
<lang Scheme>(define (cat . nums) (apply string-append (map number->string nums))) |
|||
(define (my-compare a b) (string>? (cat a b) (cat b a))) |
|||
(map (lambda (xs) (string->number (apply cat (sort xs my-compare)))) |
|||
'((1 34 3 98 9 76 45 4) (54 546 548 60)))</lang> |
|||
{{output}} |
|||
<pre> |
|||
(998764543431 6054854654) |
|||
</pre> |
|||
=={{header|Sidef}}== |
|||
{{trans|Ruby}} |
|||
<lang ruby>func maxnum(nums) { |
|||
nums.sort {|x,y| "#{y}#{x}" <=> "#{x}#{y}" }; |
|||
} |
|||
[[54, 546, 548, 60], [1, 34, 3, 98, 9, 76, 45, 4]].each { |c| |
|||
say maxnum(c).join.to_num; |
|||
}</lang> |
|||
{{out}} |
|||
<pre> |
|||
6054854654 |
|||
998764543431 |
|||
</pre> |
|||
=={{header|Smalltalk}}== |
|||
Version 1) sort by padded print strings: |
|||
{{works with|Smalltalk/X}} |
|||
<lang smalltalk>#( |
|||
(54 546 548 60) |
|||
(1 34 3 98 9 76 45 4) |
|||
) do:[:ints | |
|||
|resultString| |
|||
"sort ints by padded strings (sort a copy - literals are immudatble), |
|||
then collect their strings, then concatenate" |
|||
resultString := |
|||
((ints copy sort:[:a :b | |
|||
|pad| |
|||
pad := (a integerLog10) max:(b integerLog10). |
|||
(a printString paddedTo:pad with:$0) > (b printString paddedTo:pad with:$0)]) |
|||
collect:#printString) asStringWith:''. |
|||
Stdout printCR: resultString. |
|||
].</lang> |
|||
Version 2) alternative: sort by concatenated pair's strings: |
|||
<lang smalltalk>#( |
|||
(54 546 548 60) |
|||
(1 34 3 98 9 76 45 4) |
|||
) do:[:ints | |
|||
|resultString| |
|||
resultString := |
|||
((ints copy sort:[:a :b | e'{a}{b}' > e'{b}{a}']) "(1)" |
|||
collect:#printString) asStringWith:''. |
|||
Stdout printCR: resultString. |
|||
].</lang> |
|||
Note ¹ replace "e'{a}{b}'" by "(a printString,b printString)" in dialects, which do not support embedded expression strings. |
|||
Version 3) no need to collect the resultString; simply print the sorted list (ok, if printing is all we want): |
|||
<lang smalltalk>#( |
|||
(54 546 548 60) |
|||
(1 34 3 98 9 76 45 4) |
|||
) do:[:ints | |
|||
(ints copy sort:[:a :b | e'{a}{b}' > e'{b}{a}']) |
|||
do:[:eachNr | eachNr printOn:Stdout]. |
|||
Stdout cr. |
|||
]</lang> |
|||
Version 4) no need to generate any intermediate strings; the following will do as well: |
|||
<lang smalltalk>#( |
|||
(54 546 548 60) |
|||
(1 34 3 98 9 76 45 4) |
|||
) do:[:ints | |
|||
(ints copy sortByApplying:[:i | i log10 fractionPart]) reverseDo:#print. |
|||
Stdout cr. |
|||
]</lang> |
|||
{{out}} |
|||
<pre>6054854654 |
|||
989764543431</pre> |
|||
=={{header|Tcl}}== |
|||
<lang tcl>proc intcatsort {nums} { |
|||
lsort -command {apply {{x y} {expr {"$y$x" - "$x$y"}}}} $nums |
|||
}</lang> |
|||
Demonstrating: |
|||
<lang tcl>foreach collection { |
|||
{1 34 3 98 9 76 45 4} |
|||
{54 546 548 60} |
|||
} { |
|||
set sorted [intcatsort $collection] |
|||
puts "\[$collection\] => \[$sorted\] (concatenated: [join $sorted ""])" |
|||
}</lang> |
|||
{{out}} |
|||
<pre> |
|||
[1 34 3 98 9 76 45 4] => [9 98 76 45 4 34 3 1] (concatenated: 998764543431) |
|||
[54 546 548 60] => [60 548 546 54] (concatenated: 6054854654) |
|||
</pre> |
|||
=={{header|VBScript}}== |
|||
{{trans|BBC BASIC}} |
|||
<lang vb> |
|||
Function largestint(list) |
|||
nums = Split(list,",") |
|||
Do Until IsSorted = True |
|||
IsSorted = True |
|||
For i = 0 To UBound(nums) |
|||
If i <> UBound(nums) Then |
|||
a = nums(i) |
|||
b = nums(i+1) |
|||
If CLng(a&b) < CLng(b&a) Then |
|||
tmpnum = nums(i) |
|||
nums(i) = nums(i+1) |
|||
nums(i+1) = tmpnum |
|||
IsSorted = False |
|||
End If |
|||
End If |
|||
Next |
|||
Loop |
|||
For j = 0 To UBound(nums) |
|||
largestint = largestint & nums(j) |
|||
Next |
|||
End Function |
|||
WScript.StdOut.Write largestint(WScript.Arguments(0)) |
|||
WScript.StdOut.WriteLine |
|||
</lang> |
|||
{{Out}} |
|||
<pre> |
|||
F:\>cscript /nologo largestint.vbs 1,34,3,98,9,76,45,4 |
|||
998764543431 |
|||
F:\>cscript /nologo largestint.vbs 54,546,548,60 |
|||
6054854654 |
|||
</pre> |
|||
=={{header|Vim Script}}== |
|||
This solution is intended to be run as an Ex command within a buffer containing the integers to be processed, one per line. |
|||
<lang Vim>%s/\(.\+\)/\1\1/ | sort! | %s/\(.\+\)\1\n/\1/</lang> |
|||
;Demonstration |
|||
<lang Bash>$ paste -s nums |
|||
1 34 3 98 9 76 45 4 |
|||
$ vim -S icsort.vim nums |
|||
998764543431</lang> |
|||
=={{header|Wren}}== |
|||
{{trans|Kotlin}} |
|||
{{libheader|Wren-sort}} |
|||
<lang ecmascript>import "/sort" for Sort |
|||
var cmp = Fn.new { |x, y| |
|||
var xy = Num.fromString(x.toString + y.toString) |
|||
var yx = Num.fromString(y.toString + x.toString) |
|||
return (xy - yx).sign |
|||
} |
|||
var findLargestSequence = Fn.new { |a| |
|||
var b = Sort.merge(a, cmp) |
|||
return b[-1..0].join() |
|||
} |
|||
var arrays = [ |
|||
[1, 34, 3, 98, 9, 76, 45, 4], |
|||
[54, 546, 548, 60] |
|||
] |
|||
for (a in arrays) { |
|||
System.print("%(a) -> %(findLargestSequence.call(a))") |
|||
}</lang> |
|||
{{out}} |
|||
<pre> |
|||
[1, 34, 3, 98, 9, 76, 45, 4] -> 998764543431 |
|||
[54, 546, 548, 60] -> 6054854654 |
|||
</pre> |
|||
=={{header|zkl}}== |
|||
loop [[1 34 3 98 9 76 45 4] [54 546 548 60]] 'a -> |
|||
<lang zkl>fcn bigCI(ns){ |
|||
print largestConcInt a</lang> |
|||
ns.apply("toString").sort(fcn(a,b){ (a+b)>(b+a) }).concat(); |
|||
}</lang> |
|||
<lang zkl>bigCI(T(1, 34, 3, 98, 9, 76, 45, 4)).println(); |
|||
bigCI(T(54, 546, 548, 60)).println();</lang> |
|||
{{out}} |
|||
<pre> |
|||
998764543431 |
|||
6054854654 |
|||
</pre> |