Population count
You are encouraged to solve this task according to the task description, using any language you may know.
The population count is the number of 1s (ones) in the binary representation of a non-negative integer.
Population count is also known as:
- pop count
- popcount
- sideways sum
- bit summation
- Hamming weight
For example, 5 (which is 101 in binary) has a population count of 2.
Evil numbers are non-negative integers that have an even population count.
Odious numbers are positive integers that have an odd population count.
- Task
- write a function (or routine) to return the population count of a non-negative integer.
- all computation of the lists below should start with 0 (zero indexed).
- display the pop count of the 1st thirty powers of 3 (30, 31, 32, 33, 34, ∙∙∙ 329).
- display the 1st thirty evil numbers.
- display the 1st thirty odious numbers.
- display each list of integers on one line (which may or may not include a title), each set of integers being shown should be properly identified.
- See also
- The On-Line Encyclopedia of Integer Sequences: A000069 odious numbers.
- The On-Line Encyclopedia of Integer Sequences: A001969 evil numbers.
11l
<lang 11l>F popcount(n)
R bin(n).count(‘1’)
print((0.<30).map(i -> popcount(Int64(3) ^ i)))
[Int] evil, odious V i = 0 L evil.len < 30 | odious.len < 30
V p = popcount(i)
I (p % 2) != 0
odious.append(i)
E
evil.append(i)
i++
print(evil[0.<30]) print(odious[0.<30])</lang>
- Output:
[1, 2, 2, 4, 3, 6, 6, 5, 6, 8, 9, 13, 10, 11, 14, 15, 11, 14, 14, 17, 17, 20, 19, 22, 16, 18, 24, 30, 25, 25] [0, 3, 5, 6, 9, 10, 12, 15, 17, 18, 20, 23, 24, 27, 29, 30, 33, 34, 36, 39, 40, 43, 45, 46, 48, 51, 53, 54, 57, 58] [1, 2, 4, 7, 8, 11, 13, 14, 16, 19, 21, 22, 25, 26, 28, 31, 32, 35, 37, 38, 41, 42, 44, 47, 49, 50, 52, 55, 56, 59]
360 Assembly
Use of the old " Unnormalized Double Floating Point" feature, a bit forgotten, to have 56-bit integers. And also use of ICM (Insert Characters Under Mask) and TM (Test under Mask) to handle bits.
Let's note:
- in Normalized Double Floating Point, one is implemented X'4110000000000000'
- in Unnormalized Double Floating Point, one is implemented X'4E00000000000001'
<lang 360asm>* Population count 09/05/2019
POPCNT CSECT
USING POPCNT,R13 base register
B 72(R15) skip savearea
DC 17F'0' savearea
SAVE (14,12) save previous context
ST R13,4(R15) link backward
ST R15,8(R13) link forward
LR R13,R15 set addressability
LD F0,UN 1
STD F0,BB bb=1
MVC PG(7),=C'pow 3:' init buffer
L R10,NN nn
BCTR R10,0 nn-1
LA R9,PG+7 @pg
LA R6,0 i=0
DO WHILE=(CR,R6,LE,R10) do i=0 to nn-1
LM R0,R1,BB r0r1=bb
BAL R14,POPCOUNT call popcount(bb)
LR R1,R0 popcount(bb)
XDECO R1,XDEC edit popcount(bb)
MVC 0(3,R9),XDEC+9 output popcount(bb)
LD F0,BB bb
AW F0,BB bb*2
AW F0,BB bb*3
STD F0,BB bb=bb*3
LA R9,3(R9) @pg
LA R6,1(R6) i++
ENDDO , enddo i
XPRNT PG,L'PG print buffer
SR R7,R7 j=0
DO WHILE=(C,R7,LE,=F'1') do j=0 to 1
MVC PG,=CL132' ' clear buffer
IF LTR,R7,Z,R7 THEN if j=0 then
MVC PG(7),=C'evil: ' init buffer
ELSE , else
MVC PG(7),=C'odious:' init buffer
ENDIF , endif
LA R9,PG+7 @pg
SR R8,R8 n=0
SR R6,R6 i=0
DO WHILE=(C,R8,LT,NN) do i=0 by 1 while(n<nn)
XR R0,R0 r0=0
LR R1,R6 r1=i
BAL R14,POPCOUNT r0=popcount(i)
SRDA R0,32 ~
D R0,=F'2' popcount(i)/2
IF CR,R0,EQ,R7 THEN if popcount(i)//2=j then
LA R8,1(R8) n=n+1
XDECO R6,XDEC edit i
MVC 0(3,R9),XDEC+9 output i
LA R9,3(R9) @pg
ENDIF , endif
LA R6,1(R6) i++
ENDDO , enddo i
XPRNT PG,L'PG print buffer
LA R7,1(R7) j++
ENDDO , enddo j
L R13,4(0,R13) restore previous savearea pointer
RETURN (14,12),RC=0 restore registers from calling sav
- ------- ---- ------------------
POPCOUNT EQU * popcount(x)
ICM R0,B'1000',=X'00' zap exponant part
XR R3,R3 y=0
LA R4,56 mantissa size = 56
LOOP STC R1,CC do i=1 to 56
TM CC,X'01' if bit(x,i)=1
BNO NOTONE then{
LA R3,1(R3) y++}
NOTONE SRDA R0,1 shift right double arithmetic
BCT R4,LOOP enddo i
LR R0,R3 return(y)
BR R14 return
- ------- ---- ------------------
NN DC F'30' nn=30 BB DS D bb UN DC X'4E00000000000001' un=1 (unnormalized) PG DC CL132' ' buffer XDEC DS CL12 temp for xdeco CC DS C
REGEQU
END POPCNT </lang>
- Output:
pow 3: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 evil: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
8080 Assembly
This program uses the parity flag to test whether a number is evil or odious, and is therefore not compatible with the Z80, which reused that flag as an overflow flag. It will only run correctly on a real 8080.
<lang 8080asm> org 100h mvi e,30 ; 3^0 to 3^29 inclusive powers: push d ; Keep counter ;;; Calculate Hamming weight of pow3 lxi b,6 ; C = 6 bytes, B = counter lxi h,pow3 ham48: mov a,m ; Get byte ana a ; Clear carry hambt: ral ; Rotate into carry jnc $+4 ; Increment counter if carry set inr b ana a ; Done yet? jnz hambt ; If not, keep going dcr c ; More bytes? inx h jnz ham48 ; If not, keep going mov a,b ; Print result call outa ;;; Multiply pow3 by 3 mvi b,6 ; Make copy lxi h,pow3 lxi d,pow3c copy: mov a,m stax d inx h inx d dcr b jnz copy ;;; Multiply by 3 (add copy to it twice) lxi h,pow3c lxi d,pow3 call add48 call add48 pop d ; Restore counter dcr e ; Count down from 30 jnz powers call outnl ;;; Print first 30 evil numbers ;;; An evil number has even parity lxi b,-226 ; B=current number (start -1), C=counter evil: inr b ; Increment number jpo evil ; If odious, try next number push b ; Otherwise, output it, mov a,b call outa pop b dcr c ; Decrement counter jnz evil ; If not zero, get more numbers call outnl ;;; Print first 30 odious numbers ;;; An odious number has odd parity lxi b,-226 odious: inr b jpe odious ; If number is evil, try next number push b mov a,b call outa pop b dcr c jnz odious ;;; Print newline outnl: lxi d,nl mvi c,9 jmp 5 ;;; Print 2-digit number in A outa: lxi d,0A2Fh ; D=10, E=high digit mkdgt: inr e sub d jnc mkdgt adi '0'+10 ; Low digit push psw ; Save low digit mvi c,2 ; Print high digit call 5 pop psw ; Restore low digit mov e,a ; Print low digit mvi c,2 call 5 mvi e,' ' ; Print space mvi c,2 jmp 5 ;;; Add 48-byte number at [HL] to [DE] add48: push h ; Keep pointers push d mvi b,6 ; 6 bytes ana a ; Clear carry a48l: ldax d ; Get byte at [DE] adc m ; Add byte at [HL] stax d ; Store result at [DE] inx h ; Increment pointers inx d dcr b ; Any more bytes left? jnz a48l ; If so, do next byte pop d ; Restore pointers pop h ret nl: db 13,10,'$' pow3: db 1,0,0,0,0,0 ; pow3, starts at 1 pow3c: equ $ ; room for copy</lang>
- Output:
01 02 02 04 03 06 06 05 06 08 09 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 00 03 05 06 09 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 01 02 04 07 08 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
8086 Assembly
<lang asm> cpu 8086 bits 16 org 100h section .text ;;; Calculate hamming weights of 3^0 to 3^29. ;;; 3^29 needs a 48-bit representation, which ;;; we'll put in BP:SI:DI. xor bp,bp ; BP:SI:DI = 1 xor si,si xor di,di inc di mov cx,30 ;;; Calculate pop count of BP:SI:DI pow3s: push bp ; Keep state push si push di xor ax,ax ; AL = counter ham48: rcl bp,1 rcl si,1 rcl di,1 adc al,ah mov dx,bp or dx,si or dx,di jnz ham48 pop di ; Restore state pop si pop bp call outal ; Output ;;; Multiply by 3 push bp ; Keep state push si push di add di,di ; Mul by two (add to itself) adc si,si adc bp,bp pop ax ; Add original (making x3) add di,ax pop ax adc si,ax pop ax adc bp,ax loop pow3s call outnl ;;; Print first 30 evil numbers ;;; This is much easier, since they fit in a byte, ;;; and we only need to know whether the Hamming weight ;;; is odd or even, which is the same as the built-in ;;; parity check mov cl,30 xor bx,bx dec bx evil: inc bx ; Increment number to test jpo .next ; If parity is odd, number is not evil mov al,bl ; Otherwise, output the number call outal dec cx ; One fewer left .next: test cx,cx jnz evil ; Next evil number call outnl ;;; For the odious numbers it is the same mov cl,30 xor bx,bx dec bx odious: inc bx jpe .next ; Except this time we skip the evil numbers mov al,bl call outal dec cx .next: test cx,cx jnz odious ;;; Print newline outnl: mov ah,2 mov dl,13 int 21h mov dl,10 int 21h ret ;;; Print 2-digit number in AL outal: aam add ax,3030h xchg dx,ax xchg dl,dh mov ah,2 int 21h xchg dl,dh int 21h mov dl,' ' int 21h ret</lang>
- Output:
01 02 02 04 03 06 06 05 06 08 09 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 00 03 05 06 09 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 01 02 04 07 08 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Ada
Specification and implementation of an auxiliary package "Population_Count". The same package is used for Pernicious numbers#Ada
<lang ada>with Interfaces;
package Population_Count is
subtype Num is Interfaces.Unsigned_64; function Pop_Count(N: Num) return Natural;
end Population_Count;</lang>
<lang Ada>package body Population_Count is
function Pop_Count(N: Num) return Natural is
use Interfaces;
K5555: constant Unsigned_64 := 16#5555555555555555#;
K3333: constant Unsigned_64 := 16#3333333333333333#;
K0f0f: constant Unsigned_64 := 16#0f0f0f0f0f0f0f0f#;
K0101: constant Unsigned_64 := 16#0101010101010101#;
X: Unsigned_64 := N;
begin
X := X - (Shift_Right(X, 1) and k5555);
X := (X and k3333) + (Shift_Right(X, 2) and k3333);
X := (X + (Shift_Right(X, 4)) and K0f0f);
X := Shift_Right((x * k0101), 56);
return Natural(X);
end Pop_Count;
end Population_Count;</lang>
The main program:
<lang Ada>with Ada.Text_IO, Population_Count; use Ada.Text_IO; use Population_Count;
procedure Test_Pop_Count is
X: Num; use type Num;
begin
Put("Pop_Cnt(3**i):"); -- print pop_counts of powers of three
X := 1; -- X=3**0
for I in 1 .. 30 loop
Put(Natural'Image(Pop_Count(X)));
X := X * 3;
end loop;
New_Line;
Put("Evil: "); -- print first thirty evil numbers
X := 0;
for I in 1 .. 30 loop
while Pop_Count(X) mod 2 /= 0 loop -- X is not evil
X := X + 1;
end loop;
Put(Num'Image(X));
X := X + 1;
end loop;
New_Line;
Put("Odious: "); -- print thirty oudous numbers
X := 1;
for I in 1 .. 30 loop
while Pop_Count(X) mod 2 /= 1 loop -- X is not odious
X := X + 1;
end loop;
Put(Num'Image(X));
X := X + 1;
end loop;
New_Line;
end Test_Pop_Count;</lang>
- Output:
Pop_Cnt(3**i): 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 Evil: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 Odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
ALGOL 68
<lang algol68># returns the population count (number of bits on) of the non-negative #
- integer n #
PROC population count = ( LONG INT n )INT:
BEGIN
LONG INT number := n;
INT result := 0;
WHILE number > 0 DO
IF ODD number THEN result +:= 1 FI;
number OVERAB 2
OD;
result
END # population # ;
- population count of 3^0, 3^1, 3*2, ..., 3^29 #
LONG INT power of three := 1; print( ( "3^x pop counts:" ) ); FOR power FROM 0 TO 29 DO
print( ( " ", whole( population count( power of three ), 0 ) ) ); power of three *:= 3
OD; print( ( newline ) );
- print the first thirty evil numbers (even population count) #
INT evil count := 0; print( ( "evil numbers :" ) ); FOR n FROM 0 WHILE evil count < 30 DO
IF NOT ODD population count( n ) THEN
print( ( " ", whole( n, 0 ) ) );
evil count +:= 1
FI
OD; print( ( newline ) );
- print the first thirty odious numbers (odd population count) #
INT odious count := 0; print( ( "odious numbers:" ) ); FOR n WHILE odious count < 30 DO
IF ODD population count( n ) THEN
print( ( " ", whole( n, 0 ) ) );
odious count +:= 1
FI
OD; print( ( newline ) ) </lang>
- Output:
3^x pop counts: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 evil numbers : 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 odious numbers: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
ALGOL W
<lang algolw>begin
% returns the population count (number of bits on) of the non-negative integer n %
integer procedure populationCount( integer value n ) ;
begin
integer v, count;
v := n;
count := 0;
while v > 0 do begin
if odd( v ) then count := count + 1;
v := v div 2
end while_v_gt_0 ;
count
end populationCount ;
% returns the sum of population counts of the elements of the array n %
% the bounds of n must be 1 :: length %
integer procedure arrayPopulationCount( integer array n ( * ); integer value length ) ;
begin
integer count;
count := 0;
for i := 1 until length do count := count + populationCount( n( i ) );
count
end arrayPopulationCount ;
begin %task requirements %
integer array power( 1 :: 8 );
integer n, count, carry;
% population counts of the first 30 powers of three %
% Algol W integers are 32-bit, so we simulate 64-bit with an array of integers %
% the only operation we need is multiplication by 3 %
% we use 8 bits of each number %
% start with 3^0, which is 1 %
for i := 1 until 8 do power( i ) := 0;
power( 1 ) := 1;
write( i_w := 1, s_w := 0, "3^x population: ", arrayPopulationCount( power, 8 ) );
for p := 1 until 29 do begin
carry := 0;
for b := 1 until 8 do begin
integer bValue;
bValue := ( power( b ) * 3 ) + carry;
carry := bValue div 256;
power( b ) := bValue rem 256
end for_b ;
writeon( i_w := 1, s_w := 0, " ", arrayPopulationCount( power, 8 ) )
end for_p ;
% evil numbers (even population count) %
write( "evil numbers:" );
n := 0;
count := 0;
while count < 30 do begin
if not odd( populationCount( n ) ) then begin
writeon( i_w := 1, s_w := 0, " ", n );
count := count + 1
end if_not_odd_populationCount ;
n := n + 1
end evil_numbers_loop ;
% odious numbers (odd population count %
write( "odious numbers:" );
n := 0;
count := 0;
while count < 30 do begin
if odd( populationCount( n ) ) then begin
writeon( i_w := 1, s_w := 0, " ", n );
count := count + 1
end if_odd_populationCount ;
n := n + 1
end odious_numbers_loop
end
end.</lang>
- Output:
3^x population: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 evil numbers: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 odious numbers: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
APL
<lang APL>
APL (DYALOG APL)
popDemo←{⎕IO←0
N←⍵
⍝ popCount: Does a popCount of integers (8-32 bits) or floats (64-bits) that can be represented as integers
popCount←{
i2bits←{∊+/2⊥⍣¯1⊣⍵} ⍝ Use ⊥⍣¯1 (inverted decode) for ⊤ (encode) to automatically detect nubits needed
+/i2bits ⍵ ⍝ Count the bits
}¨
act3←popCount 3*⍳N
M←N×2
actEvil←N↑{⍵/⍨0=2|popCount ⍵}⍳M
actOdious←N↑{⍵/⍨1=2|popCount ⍵}⍳M
⎕←'powers 3'act3
⎕←'evil 'actEvil
⎕←'odious 'actOdious
⍝ Extra: Validate answers are correct
⍝ Actual answers
ans3←1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25
ansEvil←0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58
ansOdious←1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
'***Passes' '***Fails'⊃⍨(ans3≢act3)∨(actEvil≢ansEvil)∨(actOdious≢ansOdious) }
</lang>
- Output:
popDemo 30 powers 3 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 evil 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 odious 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59 ***Passes
AppleScript
Functional
<lang AppleScript>--------------------- POPULATION COUNT ---------------------
-- populationCount :: Int -> Int on populationCount(n)
-- The number of non-zero bits in the binary
-- representation of the integer n.
script go
on |λ|(x)
if 0 < x then
Just({x mod 2, x div 2})
else
Nothing()
end if
end |λ|
end script
integerSum(unfoldr(go, n))
end populationCount
TEST ---------------------------
on run
set {evens, odds} to partition(compose(even, populationCount), ¬
enumFromTo(0, 59))
unlines({"Population counts of the first 30 powers of three:", ¬
tab & showList(map(compose(populationCount, raise(3)), ¬
enumFromTo(0, 29))), ¬
"", ¬
"First thirty 'evil' numbers:", ¬
tab & showList(evens), ¬
"", ¬
"First thirty 'odious' numbers:", ¬
tab & showList(odds)})
end run
GENERIC --------------------------
-- Just :: a -> Maybe a on Just(x)
-- Constructor for an inhabited Maybe (option type) value.
-- Wrapper containing the result of a computation.
{type:"Maybe", Nothing:false, Just:x}
end Just
-- Nothing :: Maybe a
on Nothing()
-- Constructor for an empty Maybe (option type) value.
-- Empty wrapper returned where a computation is not possible.
{type:"Maybe", Nothing:true}
end Nothing
-- compose (<<<) :: (b -> c) -> (a -> b) -> a -> c
on compose(f, g)
script
property mf : mReturn(f)
property mg : mReturn(g)
on |λ|(x)
mf's |λ|(mg's |λ|(x))
end |λ|
end script
end compose
-- enumFromTo :: Int -> Int -> [Int]
on enumFromTo(m, n)
if m ≤ n then
set lst to {}
repeat with i from m to n
set end of lst to i
end repeat
lst
else
{}
end if
end enumFromTo
-- even :: Int -> Bool
on even(x)
0 = x mod 2
end even
-- foldl :: (a -> b -> a) -> a -> [b] -> a
on foldl(f, startValue, xs)
tell mReturn(f)
set v to startValue
set lng to length of xs
repeat with i from 1 to lng
set v to |λ|(v, item i of xs, i, xs)
end repeat
return v
end tell
end foldl
-- map :: (a -> b) -> [a] -> [b]
on map(f, xs)
-- The list obtained by applying f
-- to each element of xs.
tell mReturn(f)
set lng to length of xs
set lst to {}
repeat with i from 1 to lng
set end of lst to |λ|(item i of xs, i, xs)
end repeat
return lst
end tell
end map
-- mReturn :: First-class m => (a -> b) -> m (a -> b)
on mReturn(f)
-- 2nd class handler function lifted into 1st class script wrapper.
if script is class of f then
f
else
script
property |λ| : f
end script
end if
end mReturn
-- partition :: (a -> Bool) -> [a] -> ([a], [a]) on partition(f, xs)
tell mReturn(f)
set ys to {}
set zs to {}
repeat with x in xs
set v to contents of x
if |λ|(v) then
set end of ys to v
else
set end of zs to v
end if
end repeat
end tell
{ys, zs}
end partition
-- raise :: Num -> Int -> Num on raise(m)
script
on |λ|(n)
m ^ n
end |λ|
end script
end raise
-- integerSum :: [Num] -> Num
on integerSum(xs)
script addInt
on |λ|(a, b)
a + (b as integer)
end |λ|
end script
foldl(addInt, 0, xs)
end integerSum
-- intercalate :: String -> [String] -> String
on intercalate(delim, xs)
set {dlm, my text item delimiters} to ¬
{my text item delimiters, delim}
set s to xs as text
set my text item delimiters to dlm
s
end intercalate
-- showList :: [a] -> String
on showList(xs)
"[" & intercalate(",", map(my str, xs)) & "]"
end showList
-- str :: a -> String
on str(x)
x as string
end str
-- unfoldr :: (b -> Maybe (a, b)) -> b -> [a]
on unfoldr(f, v)
-- A list derived from a simple value.
-- Dual to foldr.
-- unfoldr (\b -> if b == 0 then Nothing else Just (b, b-1)) 10
-- -> [10,9,8,7,6,5,4,3,2,1]
set xr to {v, v} -- (value, remainder)
set xs to {}
tell mReturn(f)
repeat -- Function applied to remainder.
set mb to |λ|(item 2 of xr)
if Nothing of mb then
exit repeat
else -- New (value, remainder) tuple,
set xr to Just of mb
-- and value appended to output list.
set end of xs to item 1 of xr
end if
end repeat
end tell
return xs
end unfoldr
-- unlines :: [String] -> String
on unlines(xs)
-- A single string formed by the intercalation
-- of a list of strings with the newline character.
set {dlm, my text item delimiters} to ¬
{my text item delimiters, linefeed}
set s to xs as text
set my text item delimiters to dlm
s
end unlines</lang>
- Output:
Population counts of the first 30 powers of three:
[1,2,2,4,3,6,6,5,6,8,9,13,10,11,14,15,11,14,14,17,17,20,19,22,16,18,24,30,25,25]
First thirty 'evil' numbers:
[0,3,5,6,9,10,12,15,17,18,20,23,24,27,29,30,33,34,36,39,40,43,45,46,48,51,53,54,57,58]
First thirty 'odious' numbers:
[1,2,4,7,8,11,13,14,16,19,21,22,25,26,28,31,32,35,37,38,41,42,44,47,49,50,52,55,56,59]
Straightforward
<lang applescript>on popCount(n)
set counter to 0
repeat until (n is 0)
set counter to counter + n mod 2
set n to n div 2
end repeat
return counter div 1
end popCount
-- Task code: -- Get the popcounts of the first 30 powers of 3. set list1 to {} repeat with i from 0 to 29
set end of list1 to popCount(3 ^ i)
end repeat
-- Collate the integers from 0 to 59 according to the evenness or oddness of their popcounts. -- In any even number of consecutive integers, exactly half are "evil" and half "odious". Thus thirty of each here. set lists2and3 to {{}, {}} repeat with i from 0 to 59
set end of item (popCount(i) mod 2 + 1) of lists2and3 to i
end repeat
-- Arrange the results for display. set astid to AppleScript's text item delimiters set AppleScript's text item delimiters to space set {list1, list2, list3} to {list1 as text, beginning of lists2and3 as text, end of lists2and3 as text} set AppleScript's text item delimiters to linefeed set output to {"Popcounts of 1st thirty powers of 3:", list1, "1st thirty evil numbers:", list2, "1st thirty odious numbers:", list3} ¬
as text
set AppleScript's text item delimiters to astid return output</lang>
- Output:
<lang applescript>"Popcounts of 1st thirty powers of 3: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 1st thirty evil numbers: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 1st thirty odious numbers: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59"</lang>
Arturo
<lang rebol>popCount: function [num][
size select split to :string as.binary num 'x -> x="1"
]
print "population count for the first thirty powers of 3:" print map 0..29 => [popCount 3^&]
print "first thirty evil numbers" print take select 0..100 => [even? popCount &] 30
print "first thirty odious numbers" print take select 0..100 => [odd? popCount &] 30</lang>
- Output:
population count for the first thirty powers of 3: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 first thirty evil numbers 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 first thirty odious numbers 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
AutoHotkey
<lang AutoHotkey>Loop, 30 Out1 .= PopCount(3 ** (A_Index - 1)) " " Loop, 60 i := A_Index - 1 , PopCount(i) & 0x1 ? Out3 .= i " " : Out2 .= i " " MsgBox, % "3^x:`t" Out1 "`nEvil:`t" Out2 "`nOdious:`t" Out3
PopCount(x) { ;https://en.wikipedia.org/wiki/Hamming_weight#Efficient_implementation x -= (x >> 1) & 0x5555555555555555 , x := (x & 0x3333333333333333) + ((x >> 2) & 0x3333333333333333) , x := (x + (x >> 4)) & 0x0f0f0f0f0f0f0f0f return (x * 0x0101010101010101) >> 56 }</lang>
- Output:
3^x: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 Evil: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 Odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
AWK
<lang AWK>
- syntax: GAWK -f POPULATION_COUNT.AWK
- converted from VBSCRIPT
BEGIN {
nmax = 30
b = 3
n = 0
bb = 1
for (i=1; i<=nmax; i++) {
list = list pop_count(bb) " "
bb *= b
}
printf("%s^n: %s\n",b,list)
for (j=0; j<=1; j++) {
c = (j == 0) ? "evil" : "odious"
i = n = 0
list = ""
while (n < nmax) {
if (pop_count(i) % 2 == j) {
n++
list = list i " "
}
i++
}
printf("%s: %s\n",c,list)
}
exit(0)
} function pop_count(xx, xq,xr,y) {
while (xx > 0) {
xq = int(xx / 2)
xr = xx - xq * 2
if (xr == 1) { y++ }
xx = xq
}
return(y)
} </lang>
- Output:
3^n: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 evil: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
C
<lang c>#include <stdio.h>
int main() {
{
unsigned long long n = 1;
for (int i = 0; i < 30; i++) {
// __builtin_popcount() for unsigned int
// __builtin_popcountl() for unsigned long
// __builtin_popcountll() for unsigned long long
printf("%d ", __builtin_popcountll(n));
n *= 3;
}
printf("\n");
}
int od[30];
int ne = 0, no = 0;
printf("evil : ");
for (int n = 0; ne+no < 60; n++) {
if ((__builtin_popcount(n) & 1) == 0) {
if (ne < 30) {
printf("%d ", n); ne++;
}
} else {
if (no < 30) {
od[no++] = n;
}
}
}
printf("\n");
printf("odious: ");
for (int i = 0; i < 30; i++) {
printf("%d ", od[i]);
}
printf("\n");
return 0;
}</lang>
- Output:
1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 evil : 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
GCC's builtin doesn't exist prior to 3.4, and the LL version is broken in 3.4 to 4.1. In 4.2+, if the platform doesn't have a good popcount instruction or isn't enabled (e.g. not compiled with -march=native), it typically emits unoptimized code which is over 2x slower than the C below. Alternative:
<lang c>#if defined(__POPCNT__) && defined(__GNUC__) && (__GNUC__> 4 || (__GNUC__== 4 && __GNUC_MINOR__> 1))
- define HAVE_BUILTIN_POPCOUNTLL
- endif
static uint64_t bitcount64(uint64_t b) {
b -= (b >> 1) & 0x5555555555555555; b = (b & 0x3333333333333333) + ((b >> 2) & 0x3333333333333333); b = (b + (b >> 4)) & 0x0f0f0f0f0f0f0f0f; return (b * 0x0101010101010101) >> 56;
} /* For 32-bit, an 8-bit table may or may not be a little faster */ static uint32_t bitcount32(uint32_t b) {
b -= (b >> 1) & 0x55555555; b = (b & 0x33333333) + ((b >> 2) & 0x33333333); b = (b + (b >> 4)) & 0x0f0f0f0f; return (b * 0x01010101) >> 24;
}</lang>
C#
<lang csharp> using System; using System.Linq;
namespace PopulationCount {
class Program
{
private static int PopulationCount(long n)
{
string binaryn = Convert.ToString(n, 2);
return binaryn.ToCharArray().Where(t => t == '1').Count();
}
static void Main(string[] args)
{
Console.WriteLine("Population Counts:");
Console.Write("3^n : ");
int count = 0;
while (count < 30)
{
double n = Math.Pow(3f, (double)count);
int popCount = PopulationCount((long)n);
Console.Write(string.Format("{0} ", popCount));
count++;
}
Console.WriteLine();
Console.Write("Evil: ");
count = 0;
int i = 0;
while (count < 30)
{
int popCount = PopulationCount(i);
if (popCount % 2 == 0)
{
count++;
Console.Write(string.Format("{0} ", i));
}
i++;
}
Console.WriteLine();
Console.Write("Odious: ");
count = 0;
i = 0;
while (count < 30)
{
int popCount = PopulationCount(i);
if (popCount % 2 != 0)
{
count++;
Console.Write(string.Format("{0} ", i));
}
i++;
}
Console.ReadKey();
}
}
} </lang>
- Output:
Population Counts: 3^n : 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 Evil: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 Odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
C++
<lang cpp>#include <iostream>
- include <bitset>
- include <climits>
size_t popcount(unsigned long long n) {
return std::bitset<CHAR_BIT * sizeof n>(n).count();
}
int main() {
{
unsigned long long n = 1;
for (int i = 0; i < 30; i++) {
std::cout << popcount(n) << " ";
n *= 3;
}
std::cout << std::endl;
}
int od[30];
int ne = 0, no = 0;
std::cout << "evil : ";
for (int n = 0; ne+no < 60; n++) {
if ((popcount(n) & 1) == 0) {
if (ne < 30) {
std::cout << n << " "; ne++;
}
} else {
if (no < 30) {
od[no++] = n;
}
}
}
std::cout << std::endl;
std::cout << "odious: ";
for (int i = 0; i < 30; i++) {
std::cout << od[i] << " ";
}
std::cout << std::endl;
return 0;
}</lang>
- Output:
1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 evil : 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Clojure
<lang Clojure> (defn population-count [n]
(Long/bitCount n)) ; use Java inter-op
(defn exp [n pow]
(reduce * (repeat pow n)))
(defn evil? [n]
(even? (population-count n)))
(defn odious? [n]
(odd? (population-count n)))
- Clojure's support for generating "lazily-evaluated" infinite sequences can
- be used to generate the requested output sets. We'll create some infinite
- sequences, and only as many items will be computed as are "pulled" by 'take'.
(defn integers []
(iterate inc 0))
(defn powers-of-n [n]
(map #(exp n %) (integers)))
(defn evil-numbers []
(filter evil? (integers)))
(defn odious-numbers []
(filter odious? (integers)))</lang>
- Output:
(take 5 (integers)) ; ==> (0 1 2 3 4) (take 5 (powers-of-n 3)) ; ==> (1 3 9 27 81) (take 5 (evil-numbers)) ; ==> (0 3 5 6 9) ;; Population Counts for first 30 powers of 3: (take 30 (map population-count (powers-of-n 3))) ; ==> (1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25) ;; First 30 'evil' numbers: (take 30 (evil-numbers)) ; ==> (0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58) ;; First 30 'odious' numbers: (take 30 (odious-numbers)) ; ==> (1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59)
Common Lisp
<lang lisp>(format T "3^x: ~{~a ~}~%"
(loop for i below 30
collect (logcount (expt 3 i))))
(multiple-value-bind
(evil odious)
(loop for i below 60
if (evenp (logcount i)) collect i into evil
else collect i into odious
finally (return (values evil odious)))
(format T "evil: ~{~a ~}~%" evil)
(format T "odious: ~{~a ~}~%" odious))</lang>
- Output:
3^x: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 evil: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Crystal
For Crystal select|reject are inherently lazy enumerators, and has popcount for upto unsigned 64-bit integers. <lang ruby>struct Int
def evil? self >= 0 && popcount.even? end
end
puts "Powers of 3:", (0...30).map{|n| (3u64 ** n).popcount}.join(' ') # can also use &** (to prevent arithmetic overflow) puts "Evil:" , 0.step.select(&.evil?).first(30).join(' ') puts "Odious:", 0.step.reject(&.evil?).first(30).join(' ')</lang>
- Output:
Powers of 3:1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 Evil: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 Odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
D
<lang d>void main() {
import std.stdio, std.algorithm, std.range, core.bitop;
enum pCount = (ulong n) => popcnt(n & uint.max) + popcnt(n >> 32);
writefln("%s\nEvil: %s\nOdious: %s",
uint.max.iota.map!(i => pCount(3L ^^ i)).take(30),
uint.max.iota.filter!(i => pCount(i) % 2 == 0).take(30),
uint.max.iota.filter!(i => pCount(i) % 2).take(30));
}</lang>
- Output:
[1, 2, 2, 4, 3, 6, 6, 5, 6, 8, 9, 13, 10, 11, 14, 15, 11, 14, 14, 17, 17, 20, 19, 22, 16, 18, 24, 30, 25, 25] Evil: [0, 3, 5, 6, 9, 10, 12, 15, 17, 18, 20, 23, 24, 27, 29, 30, 33, 34, 36, 39, 40, 43, 45, 46, 48, 51, 53, 54, 57, 58] Odious: [1, 2, 4, 7, 8, 11, 13, 14, 16, 19, 21, 22, 25, 26, 28, 31, 32, 35, 37, 38, 41, 42, 44, 47, 49, 50, 52, 55, 56, 59]
Delphi
<lang Delphi> program Population_count;
{$APPTYPE CONSOLE}
{$R *.res}
uses
System.SysUtils, Math;
function PopulationCount(AInt: UInt64): Integer; begin
Result := 0; repeat inc(Result, (AInt and 1)); AInt := AInt div 2; until (AInt = 0);
end;
var
i, count: Integer; n: Double; popCount: Integer;
begin
Writeln('Population Counts:'#10);
Write('3^n : ');
for i := 0 to 30 do
begin
n := Math.Power(3, i);
popCount := PopulationCount(round(n));
Write(Format('%d ', [popCount]));
end;
Writeln(#10#10'Evil: ');
count := 0;
i := 0;
while (count < 30) do
begin
popCount := PopulationCount(i);
if not Odd(popCount) then
begin
inc(count);
Write(Format('%d ', [i]));
end;
inc(i);
end;
Writeln(#10#10'Odious: ');
count := 0;
i := 0;
while (count < 30) do
begin
popCount := PopulationCount(i);
if Odd(popCount) then
begin
inc(count);
Write(Format('%d ', [i]));
end;
inc(i);
end;
readln;
end.
</lang>
Elixir
<lang elixir>defmodule Population do
def count(n), do: count(<<n :: integer>>, 0)
defp count(<<>>, acc), do: acc
defp count(<<bit :: integer-1, rest :: bitstring>>, sum), do: count(rest, sum + bit) def evil?(n), do: n >= 0 and rem(count(n),2) == 0 def odious?(n), do: n >= 0 and rem(count(n),2) == 1
end
IO.puts "Population count of the first thirty powers of 3:" IO.inspect Stream.iterate(1, &(&1*3)) |> Enum.take(30) |> Enum.map(&Population.count(&1)) IO.puts "first thirty evil numbers:" IO.inspect Stream.iterate(0, &(&1+1)) |> Stream.filter(&Population.evil?(&1)) |> Enum.take(30) IO.puts "first thirty odious numbers:" IO.inspect Stream.iterate(0, &(&1+1)) |> Stream.filter(&Population.odious?(&1)) |> Enum.take(30)</lang>
- Output:
Population count of the first thirty powers of 3: [1, 2, 2, 4, 3, 6, 6, 5, 6, 8, 9, 13, 10, 11, 14, 15, 11, 14, 14, 17, 17, 20, 19, 22, 16, 18, 24, 30, 25, 25] first thirty evil numbers: [0, 3, 5, 6, 9, 10, 12, 15, 17, 18, 20, 23, 24, 27, 29, 30, 33, 34, 36, 39, 40, 43, 45, 46, 48, 51, 53, 54, 57, 58] first thirty odious numbers: [1, 2, 4, 7, 8, 11, 13, 14, 16, 19, 21, 22, 25, 26, 28, 31, 32, 35, 37, 38, 41, 42, 44, 47, 49, 50, 52, 55, 56, 59]
Erlang
<lang erlang>-module(population_count). -export([popcount/1]).
-export([task/0]).
popcount(N) ->
popcount(N,0).
popcount(0,Acc) ->
Acc;
popcount(N,Acc) ->
popcount(N div 2, Acc + N rem 2).
threes(_,0,Acc) ->
lists:reverse(Acc);
threes(Threes,N,Acc) ->
threes(Threes * 3, N-1, [popcount(Threes)|Acc]).
threes(N) ->
threes(1,N,[]).
evil(_,0,Acc) ->
lists:reverse(Acc);
evil(N,Count,Acc) ->
case popcount(N) rem 2 of
0 ->
evil(N+1,Count-1,[N|Acc]);
1 ->
evil(N+1,Count,Acc)
end.
evil(Count) ->
evil(0,Count,[]).
odious(_,0,Acc) ->
lists:reverse(Acc);
odious(N,Count,Acc) ->
case popcount(N) rem 2 of
1 ->
odious(N+1,Count-1,[N|Acc]);
0 ->
odious(N+1,Count,Acc)
end.
odious(Count) ->
odious(1,Count,[]).
task() ->
io:format("Powers of 3: ~p~n",[threes(30)]),
io:format("Evil:~p~n",[evil(30)]),
io:format("Odious:~p~n",[odious(30)]).</lang>
- Output:
<lang erlang>61> population_count:task(). Powers of 3: [1,2,2,4,3,6,6,5,6,8,9,13,10,11,14,15,11,14,14,17,17,20,19,22,16,18,24,30,25,
25]
Evil:[0,3,5,6,9,10,12,15,17,18,20,23,24,27,29,30,33,34,36,39,40,43,45,46,48,
51,53,54,57,58]
Odious:[1,2,4,7,8,11,13,14,16,19,21,22,25,26,28,31,32,35,37,38,41,42,44,47,49,
50,52,55,56,59]
ok</lang>
F#
<lang fsharp> // Population count. Nigel Galloway: February 18th., 2021 let pC n=Seq.unfold(fun n->match n/2L,n%2L with (0L,0L)->None |(n,g)->Some(g,n))n|>Seq.sum printf "pow3 :"; [0..29]|>List.iter((pown 3L)>>pC>>(printf "%3d")); printfn "" printf "evil :"; Seq.initInfinite(int64)|>Seq.filter(fun n->(pC n) &&& 1L=0L)|>Seq.take 30|>Seq.iter(printf "%3d"); printfn "" printf "odious:"; Seq.initInfinite(int64)|>Seq.filter(fun n->(pC n) &&& 1L=1L)|>Seq.take 30|>Seq.iter(printf "%3d"); printfn "" </lang>
- Output:
pow3 : 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 evil : 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Factor
<lang factor>USING: formatting kernel lists lists.lazy math math.bitwise math.functions namespaces prettyprint.config sequences ;
- 3^n ( obj -- obj' ) [ 3 swap ^ bit-count ] lmap-lazy ;
- evil ( obj -- obj' ) [ bit-count even? ] lfilter ;
- odious ( obj -- obj' ) [ bit-count odd? ] lfilter ;
100 margin set 0 lfrom [ 3^n ] [ evil ] [ odious ] tri [ 30 swap ltake list>array ] tri@ "3^n: %u\nEvil: %u\nOdious: %u\n" printf</lang>
- Output:
3^n: { 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 }
Evil: { 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 }
Odious: { 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59 }
Fermat
<lang fermat>Func Popcount(n) = if n = 0 then 0 else if 2*(n\2)=n then Popcount(n\2) else Popcount((n-1)\2)+1 fi fi. Func Odiousness(n) = p:=Popcount(n);if 2*(p\2) = p then 0 else 1 fi.
for n=0 to 29 do !Popcount(3^n);!' ' od e:=0 n:=0 while e<30 do if Odiousness(n)=0 then !n;!' ';e:=e+1 fi; n:=n+1 od e:=0 n:=0 while e<30 do if Odiousness(n)=1 then !n;!' ';e:=e+1 fi; n:=n+1 od</lang>
Forth
<lang Forth>: popcnt ( n -- u) 0 swap
BEGIN dup WHILE tuck 1 AND + swap 1 rshift REPEAT DROP ;
- odious? ( n -- t|f) popcnt 1 AND ;
- evil? ( n -- t|f) odious? 0= ;
CREATE A 30 ,
- task1 1 0 ." 3**i popcnt: "
BEGIN dup A @ < WHILE
over popcnt . 1+ swap 3 * swap
REPEAT DROP DROP CR ;
- task2 0 0 ." evil : "
BEGIN dup A @ < WHILE
over evil? IF over . 1+ THEN swap 1+ swap
REPEAT DROP DROP CR ;
- task3 0 0 ." odious : "
BEGIN dup A @ < WHILE
over odious? IF over . 1+ THEN swap 1+ swap
REPEAT DROP DROP CR ;
task1 task2 task3 BYE</lang>
- Output:
3**i popcnt: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 evil : 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 odious : 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Fortran
<lang fortran>program population_count
implicit none
integer, parameter :: i64 = selected_int_kind(18) integer(i64) :: x integer :: i, n x = 1 write(*, "(a8)", advance = "no") "3**i :" do i = 1, 30 write(*, "(i3)", advance = "no") popcnt(x) x = x * 3 end do
write(*,*)
write(*, "(a8)", advance = "no") "Evil :"
n = 0
x = 0
do while(n < 30)
if(mod(popcnt(x), 2) == 0) then
n = n + 1
write(*, "(i3)", advance = "no") x
end if
x = x + 1
end do
write(*,*)
write(*, "(a8)", advance = "no") "Odious :"
n = 0
x = 0
do while(n < 30)
if(mod(popcnt(x), 2) /= 0) then
n = n + 1
write(*, "(i3)", advance = "no") x
end if
x = x + 1
end do
contains
integer function popcnt(x)
integer(i64), intent(in) :: x integer :: i
popcnt = 0 do i = 0, 63 if(btest(x, i)) popcnt = popcnt + 1 end do
end function end program</lang>
- Output:
3**i : 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 Evil : 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 Odious : 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Free Pascal
The system unit in the RTL (run-time library) shipped with every FPC (Free Pascal compiler) distribution contains the function popCnt.
It accepts one integer parameter and is defined for all unsigned integer types.
Therefore its implementation is skipped.
<lang pascal>program populationCount(input, output, stdErr);
var
// general advice: iterator variables are _signed_
iterator: int64;
// the variable we’d like to count the set bits in
number: qWord;
// how many evil numbers we’ve already found
evilCount: int64;
// odious numbers
odiousNumber: array[1..30] of qWord;
odiousIterator: int64;
begin
// population count for powers of three
for iterator := 0 to 29 do
begin
number := round(exp(ln(3) * iterator));
write(popCnt(number):3);
end;
writeLn();
// evil numbers // (while preserving calculated odious numbers for next sub-task) evilCount := 0; odiousIterator := low(odiousNumber);
// for-loop: because we (pretend to) don’t know, // when and where we’ve found the first 30 numbers of each for iterator := 0 to high(iterator) do begin // implicit typecast: popCnt only accepts _un_-signed integers number := iterator; if odd(popCnt(number)) then begin if odiousIterator <= high(odiousNumber) then begin odiousNumber[odiousIterator] := number; inc(odiousIterator); end; end else begin if evilCount < 30 then begin write(number:20); inc(evilCount); end; end;
if evilCount + odiousIterator > 60 then begin break; end; end; writeLn();
// odious numbers for number in odiousNumber do begin write(number:20); end; writeLn(); end.</lang>
- Output:
1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25
0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58
1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Fōrmulæ
In this page you can see the solution of this task.
Fōrmulæ programs are not textual, visualization/edition of programs is done showing/manipulating structures but not text (more info). 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 transportation effects more than visualization and edition.
The option to show Fōrmulæ programs and their results is showing images. Unfortunately images cannot be uploaded in Rosetta Code.
FreeBASIC
<lang freebasic>
- define NTERMS 30
function popcount( n as ulongint ) as uinteger
if n = 0 then return 0 if n = 1 then return 1 if n mod 2 = 0 then return popcount(n/2) return 1 + popcount( (n - 1)/2 )
end function
dim as ulongint i=0, tp(0 to NTERMS-1), evil(0 to NTERMS-1),_
odious(0 to NTERMS-1), k, ne=0, no=0
while ne < NTERMS or no < NTERMS
if i<NTERMS then tp(i) = popcount(3^i)
k = popcount(i)
if k mod 2 = 0 and ne < NTERMS then
evil(ne) = i
ne += 1
endif
if k mod 2 = 1 and no < NTERMS then
odious(no) = i
no += 1
end if
i += 1
wend
dim as string s_tp = "", s_evil = "", s_odious = ""
for i = 0 to NTERMS-1
s_tp += str(tp(i))+" " s_evil += str(evil(i))+" " s_odious += str(odious(i))+" "
next i
print s_tp print s_evil print s_odious</lang>
- Output:
1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Gambas
Click this link to run this code <lang gambas>Public Sub Main() Dim sEvil, sOdious As String 'To store the output for printing Evil and Odious Dim iCount, iEvil, iOdious As Integer 'Counters
Print "First 30 numbers ^3\t"; 'Print title
For iCount = 0 To 29 'Count 30 times
Print Len(Replace(Bin(3 ^ iCount), "0", ""));; 'Get the Bin of the number, take out the '0's and the remaining
Next 'length is the Population count e.g. 3^2=9, Bin=1001, remove '0's='11', length=2
iCount = 0 'Reset iCount
Repeat 'Repeat/Until loop
If Even(Len(Replace(Bin(iCount), "0", ""))) Then 'If (as above) the result is Even then sEvil &= Str(icount) & " " 'Add it to sEvil Inc iEvil 'Increase iEvil End If If Odd(Len(Replace(Bin(iCount), "0", ""))) Then 'If (as above) the result is Odd then sOdious &= Str(icount) & " " 'Add it to sOdious Inc iOdious 'Increase iOdious End If Inc iCount 'Increase iCount
Until iEvil = 30 And iOdious = 30 'Until both iEvil and iOdious = 30 then exit the loop
Print "\n1st 30 Evil numbers =\t" & sEvil 'Print Evil Print "1st 30 Odious numbers =\t" & sOdious 'Print Odious
End</lang> Output:
First 30 numbers ^3 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 1st 30 Evil numbers = 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 1st 30 Odious numbers = 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Go
Standard Library
As of Go 1.9, this function is in the standard Library. <lang go>package main
import (
"fmt" "math/bits"
)
func main() {
fmt.Println("Pop counts, powers of 3:")
n := uint64(1) // 3^0
for i := 0; i < 30; i++ {
fmt.Printf("%d ", bits.OnesCount64(n))
n *= 3
}
fmt.Println()
fmt.Println("Evil numbers:")
var od [30]uint64
var ne, no int
for n = 0; ne+no < 60; n++ {
if bits.OnesCount64(n)&1 == 0 {
if ne < 30 {
fmt.Printf("%d ", n)
ne++
}
} else {
if no < 30 {
od[no] = n
no++
}
}
}
fmt.Println()
fmt.Println("Odious numbers:")
for _, n := range od {
fmt.Printf("%d ", n)
}
fmt.Println()
}</lang>
- Output:
Pop counts, powers of 3: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 Evil numbers: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 Odious numbers: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Implementation
Method of WP example popcount_3: <lang go>func pop64(w uint64) int {
const (
ff = 1<<64 - 1
mask1 = ff / 3
mask3 = ff / 5
maskf = ff / 17
maskp = maskf >> 3 & maskf
)
w -= w >> 1 & mask1
w = w&mask3 + w>>2&mask3
w = (w + w>>4) & maskf
return int(w * maskp >> 56)
}</lang> Method of WP example popcount_4: <lang go>func pop64(w uint64) (c int) {
for w != 0 {
w &= w - 1
c++
}
return
}</lang>
Haskell
<lang haskell>import Data.Bits (popCount)
printPops :: (Show a, Integral a) => String -> [a] -> IO () printPops title counts = putStrLn $ title ++ show (take 30 counts)
main :: IO () main = do
printPops "popcount " $ map popCount $ iterate (*3) (1 :: Integer) printPops "evil " $ filter (even . popCount) ([0..] :: [Integer]) printPops "odious " $ filter ( odd . popCount) ([0..] :: [Integer])</lang>
- Output:
popcount [1,2,2,4,3,6,6,5,6,8,9,13,10,11,14,15,11,14,14,17,17,20,19,22,16,18,24,30,25,25] evil [0,3,5,6,9,10,12,15,17,18,20,23,24,27,29,30,33,34,36,39,40,43,45,46,48,51,53,54,57,58] odious [1,2,4,7,8,11,13,14,16,19,21,22,25,26,28,31,32,35,37,38,41,42,44,47,49,50,52,55,56,59]
Or, if we want to write our own popCount, perhaps something like:
<lang haskell>import Data.List (partition, unfoldr) import Data.Bifoldable (biList) import Data.Tuple (swap) import Data.Bool (bool)
-- POPCOUNT ------------------------------------------------------------- popCount :: Int -> Int popCount =
sum . unfoldr ((bool Nothing . Just . swap . flip quotRem 2) <*> (0 <))
-- TEST ----------------------------------------------------------------- main :: IO () main =
mapM_ putStrLn $
zipWith
(\k xs -> k ++ ":\n" ++ show xs ++ "\n")
["Population count of powers of 3", "evil", "odious"]
((popCount . (3 ^) <$> [0 .. 29]) :
biList (partition (even . popCount) [0 .. 59]))</lang>
- Output:
Population count of powers of 3: [1,2,2,4,3,6,6,5,6,8,9,13,10,11,14,15,11,14,14,17,17,20,19,22,16,18,24,30,25,25] evil: [0,3,5,6,9,10,12,15,17,18,20,23,24,27,29,30,33,34,36,39,40,43,45,46,48,51,53,54,57,58] odious: [1,2,4,7,8,11,13,14,16,19,21,22,25,26,28,31,32,35,37,38,41,42,44,47,49,50,52,55,56,59]
Idris
<lang Idris>module Main import Data.Vect
isOdd : (x : Int) -> Bool isOdd x = case mod x 2 of
0 => False
1 => True
popcnt : Int -> Int popcnt 0 = 0 popcnt x = case isOdd x of
False => popcnt (shiftR x 1) True => 1 + popcnt (shiftR x 1)
isOdious : Int -> Bool isOdious k = isOdd (popcnt k)
isEvil : Int -> Bool isEvil k = not (isOdious k)
filterUnfoldN : (n : Nat) ->
(pred : Int -> Bool) -> (f : Int -> a) ->
(next : Int -> Int) -> (seed : Int) ->
Vect n a
filterUnfoldN Z pred f next seed = [] filterUnfoldN (S k) pred f next seed =
if pred seed then (f seed) :: filterUnfoldN k pred f next (next seed) else filterUnfoldN (S k) pred f next (next seed)
printCompact : (Show a) => Vect n a -> IO () printCompact v = putStrLn (unwords (map show (toList v)))
main : IO () main = do putStr "popcnt(3**i): "
printCompact (filterUnfoldN 30 (\_ => True) popcnt (3 *) 1)
putStr "Evil: "
printCompact (filterUnfoldN 30 isEvil id (1 +) 0)
putStr "Odious: "
printCompact (filterUnfoldN 30 isOdious id (1 +) 0)</lang>
- Output:
popcnt(3**i): 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 Evil: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 Odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
J
Implementation:
<lang J>countPopln=: +/"1@#: isOdd=: 1 = 2&| isEven=: 0 = 2&|</lang>
Task:
<lang J> countPopln 3^i.30x 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25
30{.(#~ isOdd@countPopln) i. 100 NB. odd population count (aka "ODious numbers")
1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
30{.(#~ isEven@countPopln) i. 100 NB. even population count (aka "EVil numbers")
0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58</lang>
Java
<lang java>import java.math.BigInteger;
public class PopCount {
public static void main(String[] args) {
{ // with int System.out.print("32-bit integer: "); int n = 1; for (int i = 0; i < 20; i++) { System.out.printf("%d ", Integer.bitCount(n)); n *= 3; } System.out.println(); } { // with long System.out.print("64-bit integer: "); long n = 1; for (int i = 0; i < 30; i++) { System.out.printf("%d ", Long.bitCount(n)); n *= 3; } System.out.println(); } { // with BigInteger System.out.print("big integer : "); BigInteger n = BigInteger.ONE; BigInteger three = BigInteger.valueOf(3); for (int i = 0; i < 30; i++) { System.out.printf("%d ", n.bitCount()); n = n.multiply(three); } System.out.println(); }
int[] od = new int[30]; int ne = 0, no = 0; System.out.print("evil : "); for (int n = 0; ne+no < 60; n++) { if ((Integer.bitCount(n) & 1) == 0) { if (ne < 30) { System.out.printf("%d ", n); ne++; } } else { if (no < 30) { od[no++] = n; } } } System.out.println(); System.out.print("odious : "); for (int n : od) { System.out.printf("%d ", n); } System.out.println();
}
}</lang>
- Output:
32-bit integer: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 64-bit integer: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 big integer : 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 evil : 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 odious : 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
JavaScript
ES6
<lang JavaScript>(() => {
'use strict';
// populationCount :: Int -> Int
const populationCount = n =>
// The number of non-zero bits in the binary
// representation of the integer n.
sum(unfoldr(
x => 0 < x ? (
Just(Tuple(x % 2)(Math.floor(x / 2)))
) : Nothing()
)(n));
// ----------------------- TEST ------------------------
// main :: IO ()
const main = () => {
const [evens, odds] = Array.from(
partition(compose(even, populationCount))(
enumFromTo(0)(59)
)
);
return [
'Population counts of the first 30 powers of three:',
` [${enumFromTo(0)(29).map(
compose(populationCount, raise(3))
).join(',')}]`,
"\nFirst thirty 'evil' numbers:",
` [${[evens.join(',')]}]`,
"\nFirst thirty 'odious' numbers:",
` [${odds.join(',')}]`
].join('\n');
};
// ----------------- GENERIC FUNCTIONS -----------------
// Just :: a -> Maybe a
const Just = x => ({
type: 'Maybe',
Nothing: false,
Just: x
});
// Nothing :: Maybe a
const Nothing = () => ({
type: 'Maybe',
Nothing: true,
});
// Tuple (,) :: a -> b -> (a, b)
const Tuple = a =>
b => ({
type: 'Tuple',
'0': a,
'1': b,
length: 2
});
// compose (<<<) :: (b -> c) -> (a -> b) -> a -> c
const compose = (...fs) =>
// A function defined by the right-to-left
// composition of all the functions in fs.
fs.reduce(
(f, g) => x => f(g(x)),
x => x
);
// enumFromTo :: Int -> Int -> [Int]
const enumFromTo = m =>
n => !isNaN(m) ? (
Array.from({
length: 1 + n - m
}, (_, i) => m + i)
) : enumFromTo_(m)(n);
// even :: Int -> Bool
const even = n =>
// True if n is an even number.
0 === n % 2;
// partition :: (a -> Bool) -> [a] -> ([a], [a])
const partition = p =>
// A tuple of two lists - those elements in
// xs which match p, and those which don't.
xs => ([...xs]).reduce(
(a, x) =>
p(x) ? (
Tuple(a[0].concat(x))(a[1])
) : Tuple(a[0])(a[1].concat(x)),
Tuple([])([])
);
// raise :: Num -> Int -> Num
const raise = x =>
// X to the power of n.
n => Math.pow(x, n);
// sum :: [Num] -> Num
const sum = xs =>
// The numeric sum of all values in xs.
xs.reduce((a, x) => a + x, 0);
// unfoldr :: (b -> Maybe (a, b)) -> b -> [a]
const unfoldr = f =>
v => {
const xs = [];
let xr = [v, v];
while (true) {
const mb = f(xr[1]);
if (mb.Nothing) {
return xs
} else {
xr = mb.Just;
xs.push(xr[0])
}
}
};
// --- return main();
})();</lang>
- Output:
Population counts of the first 30 powers of three:
[1,2,2,4,3,6,6,5,6,8,9,13,10,11,14,15,11,14,14,17,17,20,19,22,16,18,24,30,25,25]
First thirty 'evil' numbers:
[0,3,5,6,9,10,12,15,17,18,20,23,24,27,29,30,33,34,36,39,40,43,45,46,48,51,53,54,57,58]
First thirty 'odious' numbers:
[1,2,4,7,8,11,13,14,16,19,21,22,25,26,28,31,32,35,37,38,41,42,44,47,49,50,52,55,56,59]
jq
<lang jq>def popcount:
def bin: recurse( if . == 0 then empty else ./2 | floor end ) % 2; [bin] | add;
def firstN(count; condition):
if count > 0 then if condition then ., (1+.| firstN(count-1; condition)) else (1+.) | firstN(count; condition) end else empty end;
def task:
def pow(n): . as $m | reduce range(0;n) as $i (1; . * $m);
"The pop count of the first thirty powers of 3:", [range(0;30) as $n | 3 | pow($n) | popcount],
"The first thirty evil numbers:", [0 | firstN(30; (popcount % 2) == 0)],
"The first thirty odious numbers:", [0 | firstN(30; (popcount % 2) == 1)]
task</lang>
- Output:
$ jq -n -r -c -f Population_count.jq The pop count of the first thirty powers of 3: [1,2,2,4,3,6,6,5,6,8,9,13,10,11,14,15,11,14,14,17,17,20,19,22,16,18,24,30,25,25] The first thirty evil numbers: [0,3,5,6,9,10,12,15,17,18,20,23,24,27,29,30,33,34,36,39,40,43,45,46,48,51,53,54,57,58] The first thirty odious numbers: [1,2,4,7,8,11,13,14,16,19,21,22,25,26,28,31,32,35,37,38,41,42,44,47,49,50,52,55,56,59]
Julia
<lang julia>println("First 3 ^ i, up to 29 pop. counts: ", join((count_ones(3 ^ n) for n in 0:29), ", ")) println("Evil numbers: ", join(filter(x -> iseven(count_ones(x)), 0:59), ", ")) println("Odious numbers: ", join(filter(x -> isodd(count_ones(x)), 0:59), ", "))</lang>
- Output:
First 3 ^ i, up to 29 pop. counts: 1, 2, 2, 4, 3, 6, 6, 5, 6, 8, 9, 13, 10, 11, 14, 15, 11, 14, 14, 17, 17, 20, 19, 22, 16, 18, 24, 30, 25, 25 Evil numbers: 0, 3, 5, 6, 9, 10, 12, 15, 17, 18, 20, 23, 24, 27, 29, 30, 33, 34, 36, 39, 40, 43, 45, 46, 48, 51, 53, 54, 57, 58 Odious numbers: 1, 2, 4, 7, 8, 11, 13, 14, 16, 19, 21, 22, 25, 26, 28, 31, 32, 35, 37, 38, 41, 42, 44, 47, 49, 50, 52, 55, 56, 59
Kotlin
<lang scala>// version 1.0.6
fun popCount(n: Long) = when {
n < 0L -> throw IllegalArgumentException("n must be non-negative")
else -> java.lang.Long.bitCount(n)
}
fun main(args: Array<String>) {
println("The population count of the first 30 powers of 3 are:")
var pow3 = 1L
for (i in 1..30) {
print("${popCount(pow3)} ")
pow3 *= 3L
}
println("\n")
println("The first thirty evil numbers are:")
var count = 0
var i = 0
while (true) {
val pc = popCount(i.toLong())
if (pc % 2 == 0) {
print("$i ")
if (++count == 30) break
}
i++
}
println("\n")
println("The first thirty odious numbers are:")
count = 0
i = 1
while (true) {
val pc = popCount(i.toLong())
if (pc % 2 == 1) {
print("$i ")
if (++count == 30) break
}
i++
}
println()
}</lang>
- Output:
The population count of the first 30 powers of 3 are: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 The first thirty evil numbers are: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 The first thirty odious numbers are: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Lua
<lang Lua>-- Take decimal number, return binary string function dec2bin (n)
local bin, bit = ""
while n > 0 do
bit = n % 2
n = math.floor(n / 2)
bin = bit .. bin
end
return bin
end
-- Take decimal number, return population count as number function popCount (n)
local bin, count = dec2bin(n), 0
for pos = 1, bin:len() do
if bin:sub(pos, pos) == "1" then count = count + 1 end
end
return count
end
-- Implement task requirements function firstThirty (mode)
local numStr, count, n, remainder = "", 0, 0
if mode == "Evil" then remainder = 0 else remainder = 1 end
while count < 30 do
if mode == "3^x" then
numStr = numStr .. popCount(3 ^ count) .. " "
count = count + 1
else
if popCount(n) % 2 == remainder then
numStr = numStr .. n .. " "
count = count + 1
end
n = n + 1
end
end
print(mode .. ":" , numStr)
end
-- Main procedure firstThirty("3^x") firstThirty("Evil") firstThirty("Odious")</lang>
- Output:
3^x: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 Evil: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 Odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
MAD
<lang MAD> NORMAL MODE IS INTEGER
INTERNAL FUNCTION LOWBIT.(K) = K-K/2*2
R FUNCTION TO CALC POP COUNT
INTERNAL FUNCTION(N)
ENTRY TO POPCNT.
RSLT = 0
PCTNUM = N
LOOP PCTNXT = PCTNUM/2
RSLT = RSLT + PCTNUM-PCTNXT*2
PCTNUM = PCTNXT
WHENEVER PCTNUM.NE.0, TRANSFER TO LOOP
FUNCTION RETURN RSLT
END OF FUNCTION
R POP COUNT OF 3^0 TO 3^29
POW3 = 1
THROUGH P3CNT, FOR I=0, 1, I.GE.30
PRINT FORMAT P3FMT, I, POPCNT.(POW3)
P3CNT POW3 = POW3 * 3
VECTOR VALUES P3FMT = $15HPOP COUNT OF 3^,I2,2H: ,I3*$
R EVIL AND ODIOUS NUMBERS
PRINT COMMENT$ $
PRINT COMMENT$ FIRST 30 EVIL NUMBERS ARE$
SEEN = 1
THROUGH EVIL, FOR I=0, 1, SEEN.GE.30
WHENEVER LOWBIT.(POPCNT.(I)).E.0
PRINT FORMAT NUMFMT,I
SEEN = SEEN + 1
EVIL END OF CONDITIONAL
PRINT COMMENT$ $
PRINT COMMENT$ FIRST 30 ODIOUS NUMBERS ARE$
SEEN = 1
THROUGH ODIOUS, FOR I=0, 1, SEEN.GE.30
WHENEVER LOWBIT.(POPCNT.(I)).E.1
PRINT FORMAT NUMFMT,I
SEEN = SEEN + 1
ODIOUS END OF CONDITIONAL
VECTOR VALUES NUMFMT = $I2*$
END OF PROGRAM</lang>
- Output:
POP COUNT OF 3^ 0: 1 POP COUNT OF 3^ 1: 2 POP COUNT OF 3^ 2: 2 POP COUNT OF 3^ 3: 4 POP COUNT OF 3^ 4: 3 POP COUNT OF 3^ 5: 6 POP COUNT OF 3^ 6: 6 POP COUNT OF 3^ 7: 5 POP COUNT OF 3^ 8: 6 POP COUNT OF 3^ 9: 8 POP COUNT OF 3^10: 9 POP COUNT OF 3^11: 13 POP COUNT OF 3^12: 10 POP COUNT OF 3^13: 11 POP COUNT OF 3^14: 14 POP COUNT OF 3^15: 15 POP COUNT OF 3^16: 11 POP COUNT OF 3^17: 14 POP COUNT OF 3^18: 14 POP COUNT OF 3^19: 17 POP COUNT OF 3^20: 17 POP COUNT OF 3^21: 20 POP COUNT OF 3^22: 19 POP COUNT OF 3^23: 22 POP COUNT OF 3^24: 16 POP COUNT OF 3^25: 18 POP COUNT OF 3^26: 24 POP COUNT OF 3^27: 30 POP COUNT OF 3^28: 25 POP COUNT OF 3^29: 25 FIRST 30 EVIL NUMBERS ARE 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 FIRST 30 ODIOUS NUMBERS ARE 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56
Mathematica
<lang Mathematica>popcount[n_Integer] := IntegerDigits[n, 2] // Total Print["population count of powers of 3"] popcount[#] & /@ (3^Range[0, 30]) (*******) evilQ[n_Integer] := popcount[n] // EvenQ evilcount = 0; evillist = {}; i = 0; While[evilcount < 30,
If[evilQ[i], AppendTo[evillist, i]; evilcount++]; i++ ]
Print["first thirty evil numbers"] evillist (*******) odiousQ[n_Integer] := popcount[n] // OddQ odiouscount = 0; odiouslist = {}; i = 0; While[odiouscount < 30,
If[odiousQ[i], AppendTo[odiouslist, i]; odiouscount++]; i++ ]
Print["first thirty odious numbers"] odiouslist</lang>
- Output:
population count of powers of 3
{1, 2, 2, 4, 3, 6, 6, 5, 6, 8, 9, 13, 10, 11, 14, 15, 11, 14, 14, 17, 17, 20, 19, 22, 16, 18, 24, 30, 25, 25, 25}
first thirty evil numbers
{0, 3, 5, 6, 9, 10, 12, 15, 17, 18, 20, 23, 24, 27, 29, 30, 33, 34, 36, 39, 40, 43, 45, 46, 48, 51, 53, 54, 57, 58}
first thirty odious numbers
{1, 2, 4, 7, 8, 11, 13, 14, 16, 19, 21, 22, 25, 26, 28, 31, 32, 35, 37, 38, 41, 42, 44, 47, 49, 50, 52, 55, 56, 59}
min
<lang min>(2 over over mod 'div dip) :divmod2
(
:n () =list (n 0 >) (n divmod2 list append #list @n) while list (1 ==) filter size
) :pop-count
(:n 0 () (over swap append 'succ dip) n times) :iota
"3^n: " print! 30 iota (3 swap pow int pop-count) map puts! 60 iota (pop-count odd?) partition "Evil: " print! puts! "Odious: " print! puts!</lang>
- Output:
3^n: (1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25) Evil: (0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58) Odious: (1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59)
Nim
<lang nim>import bitops import strformat
var n = 1 write(stdout, "3^x :") for i in 0..<30:
write(stdout, fmt"{popcount(n):2} ")
n *= 3
var od: array[30, int] var ne, no = 0 n = 0 write(stdout, "\nevil :") while ne + no < 60:
if (popcount(n) and 1) == 0:
if ne < 30:
write(stdout, fmt"{n:2} ")
inc ne
else:
if no < 30:
od[no] = n
inc no
inc n
write(stdout, "\nodious:") for i in 0..<30:
write(stdout, fmt"{od[i]:2} ")
write(stdout, '\n')</lang>
- Output:
3^x : 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 evil : 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Another version, in functional style, with most computations done at compile time: <lang Nim>import bitops, math, sequtils, strutils
const
N = 30 popcounts = toSeq(0..<N).mapIt(popcount(3^it)) mapping = toSeq(0..<(2 * N)).mapIt((it, it.popcount)) evil = mapping.filterIt((it[1] and 1) == 0).mapIt(it[0]) odious = mapping.filterIt((it[1] and 1) != 0).mapIt(it[0])
echo "3^n: ", popcounts.mapIt(($it).align(2)).join(" ") echo "evil: ", evil.mapIt(($it).align(2)).join(" ") echo "odious:", odious.mapIt(($it).align(2)).join(" ")</lang>
- Output:
3^n: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 evil: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Oforth
<lang oforth>: popcount(n)
0 while ( n ) [ n isOdd + n bitRight(1) ->n ] ;
- test
| i count |
30 seq map(#[ 3 swap 1- pow ]) map(#popcount) println 0 ->count 0 while( count 30 <> ) [ dup popcount isEven ifTrue: [ dup . count 1+ ->count ] 1+ ] drop printcr
0 ->count 0 while( count 30 <> ) [ dup popcount isOdd ifTrue: [ dup . count 1+ ->count ] 1+ ] drop ;</lang>
- Output:
>test [1, 2, 2, 4, 3, 6, 6, 5, 6, 8, 9, 13, 10, 11, 14, 15, 11, 14, 14, 17, 17, 20, 19, 22, 16, 18, 24, 30, 25, 25] 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59 ok
PARI/GP
<lang parigp>vector(30,n,hammingweight(3^(n-1))) od=select(n->hammingweight(n)%2,[0..100]); ev=setminus([0..100],od); ev[1..30] od[1..30]</lang>
- Output:
%1 = [1, 2, 2, 4, 3, 6, 6, 5, 6, 8, 9, 13, 10, 11, 14, 15, 11, 14, 14, 17, 17, 20, 19, 22, 16, 18, 24, 30, 25, 25] %2 = [0, 3, 5, 6, 9, 10, 12, 15, 17, 18, 20, 23, 24, 27, 29, 30, 33, 34, 36, 39, 40, 43, 45, 46, 48, 51, 53, 54, 57, 58] %3 = [1, 2, 4, 7, 8, 11, 13, 14, 16, 19, 21, 22, 25, 26, 28, 31, 32, 35, 37, 38, 41, 42, 44, 47, 49, 50, 52, 55, 56, 59]
Pascal
Like Ada a unit is used. <lang pascal>unit popcount; {$IFDEF FPC}
{$MODE DELPHI}
{$OPTIMIZATION ON,ASMCSE,CSE,PEEPHOLE}
{$Smartlink OFF}
{$ENDIF}
interface
function popcnt(n:Uint64):integer;overload; function popcnt(n:Uint32):integer;overload; function popcnt(n:Uint16):integer;overload; function popcnt(n:Uint8):integer;overload;
implementation const //K1 = $0101010101010101;
K33 = $3333333333333333; K55 = $5555555555555555; KF1 = $0F0F0F0F0F0F0F0F; KF2 = $00FF00FF00FF00FF; KF4 = $0000FFFF0000FFFF; KF8 = $00000000FFFFFFFF;
{ function popcnt64(n:Uint64):integer; begin
n := n- (n shr 1) AND K55; n := (n AND K33)+ ((n shr 2) AND K33); n := (n + (n shr 4)) AND KF1; n := (n*k1) SHR 56; result := n;
end; } function popcnt(n:Uint64):integer;overload; // on Intel Haswell 2x faster for fpc 32-Bit begin
n := (n AND K55)+((n shr 1) AND K55); n := (n AND K33)+((n shr 2) AND K33); n := (n AND KF1)+((n shr 4) AND KF1); n := (n AND KF2)+((n shr 8) AND KF2); n := (n AND KF4)+((n shr 16) AND KF4); n := (n AND KF8)+ (n shr 32); result := n;
end;
function popcnt(n:Uint32):integer;overload; var
c,b : NativeUint;
begin
b := n; c := (b shr 1) AND NativeUint(K55); b := (b AND NativeUint(K55))+C; c := ((b shr 2) AND NativeUint(K33));b := (b AND NativeUint(K33))+C; c:= ((b shr 4) AND NativeUint(KF1)); b := (b AND NativeUint(KF1))+c; c := ((b shr 8) AND NativeUint(KF2));b := (b AND NativeUint(KF2))+c; c := b shr 16; b := (b AND NativeUint(KF4))+ C; result := b;
end;
function popcnt(n:Uint16):integer;overload; var
c,b : NativeUint;
begin
b := n; c := (b shr 1) AND NativeUint(K55); b := (b AND NativeUint(K55))+C; c :=((b shr 2) AND NativeUint(K33)); b := (b AND NativeUint(K33))+C; c:= ((b shr 4) AND NativeUint(KF1)); b := (b AND NativeUint(KF1))+c; c := b shr 8; b := (b AND NativeUint(KF2))+c; result := b;
end;
function popcnt(n:Uint8):integer;overload; var
c,b : NativeUint;
begin
b := n; c := (b shr 1) AND NativeUint(K55); b := (b AND NativeUint(K55))+C; c :=((b shr 2) AND NativeUint(K33));b := (b AND NativeUint(K33))+C; c:= b shr 4; result := (b AND NativeUint(KF1))+c;
end;
Begin End.</lang> The program <lang pascal>program pcntTest; uses
sysutils,popCount;
function Odious(n:Uint32):boolean;inline; Begin
Odious := boolean(PopCnt(n) AND 1)
end;
function EvilNumber(n:Uint32):boolean;inline; begin
EvilNumber := boolean(NOT(PopCnt(n)) AND 1);
end;
var
s : String; i : Uint64; k : LongWord;
Begin
s :='PopCnt 3^i :'; i:= 1; For k := 1 to 30 do Begin s := s+InttoStr(PopCnt(i)) +' '; i := 3*i; end; writeln(s);writeln;
s:='Evil numbers :';i := 0;k := 0;
repeat
IF EvilNumber(i) then
Begin
inc(k);s := s+InttoStr(i) +' ';
end;
inc(i);
until k = 30;
writeln(s);writeln;s:=;
s:='Odious numbers :';i := 0;k := 0;
repeat
IF Odious(i) then
Begin
inc(k);s := s+InttoStr(i) +' ';
end;
inc(i);
until k = 30;
writeln(s);
end.</lang>
- Output
PopCnt 3^i :1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 Evil numbers :0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 Odious numbers :1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Some processors define the card function, which can be used in conjunction with sets:
<lang pascal>var
i: integer;
f: set of 0..(bitSizeOf(i)-1) absolute i; // same address as i, but different interpretation
begin
writeLn(card(f));
end;</lang>
Perl
We'll emulate infinite lists with closures.
<lang perl>use strict; use warnings;
sub population_count {
my $n = shift;
die "argument can't be negative" if $n < 0;
my $c;
for ($c = 0; $n; $n >>= 1) {
$c += $n & 1;
}
$c;
}
print join ' ', map { population_count(3**$_) } 0 .. 30 - 1; print "\n"; sub evil {
my $i = 0;
sub { $i++ while population_count($i) % 2; $i++ }
} sub odious {
my $i = 0;
sub { $i++ until population_count($i) % 2; $i++ }
}
my ($evil, $odious) = (evil, odious); my (@evil, @odious); for (1 .. 30) {
push @evil, $evil->(); push @odious, $odious->();
}
printf "Evil : %s\n", join ' ', @evil; printf "Odious: %s\n", join ' ', @odious;</lang>
- Output:
1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 Evil : 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 Odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
A faster population count can be done with pack/unpack:
<lang>say unpack("%b*",pack "J*", 1234567); # J = UV</lang>
Various modules can also perform a population count, with the first of these being faster than the pack/unpack builtins. The first three easily support bigints, the last will with some adjustment. <lang perl>use ntheory qw/hammingweight/; say hammingweight(1234567);
use Math::GMPz qw/Rmpz_popcount/; say Rmpz_popcount(Math::GMPz->new(1234567));
use Math::BigInt; say 0 + (Math::BigInt->new(1234567)->as_bin() =~ tr/1//);
use Bit::Vector; say Bit::Vector->new_Dec(64,1234567)->Norm;</lang>
Phix
<lang Phix>function pop_count(atom n)
if n<0 then ?9/0 end if
integer res = 0
while n!=0 do
res += and_bits(n,1)
n = floor(n/2)
end while
return res
end function
sequence s = {} for i=0 to 29 do
s &= pop_count(power(3,i))
end for puts(1,"3^x pop_counts:") ?s
procedure eo(integer b0, string name)
integer k=0, l=1
while l<=30 do
if and_bits(pop_count(k),1)=b0 then
s[l] = k
l += 1
end if
k += 1
end while
puts(1,name&" numbers:") ?s
end procedure eo(0," evil") eo(1,"odious")</lang>
- Output:
3^x pop_counts:{1,2,2,4,3,6,6,5,6,8,9,13,10,11,14,15,11,14,14,17,17,20,19,22,16,18,24,30,25,25}
evil numbers:{0,3,5,6,9,10,12,15,17,18,20,23,24,27,29,30,33,34,36,39,40,43,45,46,48,51,53,54,57,58}
odious numbers:{1,2,4,7,8,11,13,14,16,19,21,22,25,26,28,31,32,35,37,38,41,42,44,47,49,50,52,55,56,59}
PHP
<lang PHP> function convertToBinary($integer) {
$binary = "";
do {
$quotient = (int) ($integer / 2);
$binary .= $integer % 2;
$integer = $quotient;
} while ($quotient > 0);
return $binary;
}
function getPopCount($integer) {
$binary = convertToBinary($integer); $offset = 0; $popCount = 0;
do {
$pos = strpos($binary, "1", $offset);
if($pos !== FALSE) $popCount++;
$offset = $pos + 1;
} while ($pos !== FALSE);
return $popCount;
}
function print3PowPopCounts() {
for ($p = 0; $p < 30; $p++) {
echo " " . getPopCount(3 ** $p);
}
}
function printFirst30Evil() {
$counter = 0; $pops = 0;
while ($pops < 30) {
$popCount = getPopCount($counter);
if ($popCount % 2 == 0) {
echo " " . $counter;
$pops++;
}
$counter++;
}
}
function printFirst30Odious() {
$counter = 1; $pops = 0;
while ($pops < 30) {
$popCount = getPopCount($counter);
if ($popCount % 2 != 0) {
echo " " . $counter;
$pops++;
}
$counter++;
}
}
echo "3 ^ x pop counts:"; print3PowPopCounts();
echo "\nfirst 30 evil numbers:"; printFirst30Evil();
echo "\nfirst 30 odious numbers:"; printFirst30Odious(); </lang>
- Output:
03 ^ x pop counts: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 first 30 evil numbers: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 first 30 odious numbers: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
PicoLisp
<lang PicoLisp>(de popz (N)
(cnt
'((N) (= "1" N))
(chop (bin N)) ) )
(println
'pops:
(mapcar
'((N) (popz (** 3 N)))
(range 0 29) ) )
(setq N -1) (println
'evil:
(make
(for (C 0 (> 30 C))
(unless (bit? 1 (popz (inc 'N)))
(link N)
(inc 'C) ) ) ) )
(setq N -1) (println
'odio:
(make
(for (C 0 (> 30 C))
(when (bit? 1 (popz (inc 'N)))
(link N)
(inc 'C) ) ) ) )</lang>
- Output:
pops: (1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25) evil: (0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58) odio: (1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59)
PowerShell
<lang PowerShell> function pop-count($n) {
(([Convert]::ToString($n, 2)).toCharArray() | where {$_ -eq '1'}).count
} "pop_count 3^n: $(1..29 | foreach -Begin {$n = 1; (pop-count $n)} -Process {$n = 3*$n; (pop-count $n)} )" "even pop_count: $($m = $n = 0; while($m -lt 30) {if(0 -eq ((pop-count $n)%2)) {$m += 1; $n}; $n += 1} )" "odd pop_count: $($m = $n = 0; while($m -lt 30) {if(1 -eq ((pop-count $n)%2)) {$m += 1; $n}; $n += 1} )" </lang> Output:
pop_count 3^n: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 even pop_count: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 odd pop_count: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
PureBasic
<lang PureBasic>Procedure.i PopCount(n.i) : ProcedureReturn CountString(Bin(Pow(3,n)),"1") : EndProcedure Procedure PutR(v.i) : Print(RSet(Str(v),3)) : EndProcedure
If OpenConsole()
NewList ne() : NewList no()
i=0
While ListSize(ne())+ListSize(no())<60
If CountString(Bin(i),"1")%2=0 : AddElement(ne()) : ne()=i
Else : AddElement(no()) : no()=i : EndIf
i+1
Wend
Print("3^i [i=0..29]") : For i=0 To 29 : PutR(PopCount(i)) : Next : PrintN("")
Print("Evil numbers ") : ForEach ne() : PutR(ne()) : Next : PrintN("")
Print("Odious numb..") : ForEach no() : PutR(no()) : Next : Input()
EndIf</lang>
- Output:
3^i [i=0..29] 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 Evil numbers 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 Odious numb.. 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Python
Procedural
<lang python>>>> def popcount(n): return bin(n).count("1") ... >>> [popcount(3**i) for i in range(30)] [1, 2, 2, 4, 3, 6, 6, 5, 6, 8, 9, 13, 10, 11, 14, 15, 11, 14, 14, 17, 17, 20, 19, 22, 16, 18, 24, 30, 25, 25] >>> evil, odious, i = [], [], 0 >>> while len(evil) < 30 or len(odious) < 30: ... p = popcount(i) ... if p % 2: odious.append(i) ... else: evil.append(i) ... i += 1 ... >>> evil[:30] [0, 3, 5, 6, 9, 10, 12, 15, 17, 18, 20, 23, 24, 27, 29, 30, 33, 34, 36, 39, 40, 43, 45, 46, 48, 51, 53, 54, 57, 58] >>> odious[:30] [1, 2, 4, 7, 8, 11, 13, 14, 16, 19, 21, 22, 25, 26, 28, 31, 32, 35, 37, 38, 41, 42, 44, 47, 49, 50, 52, 55, 56, 59] >>> </lang>
Python: Kernighans' algorithm
The algorithm is explained here. Replace popcount with pop_kernighan in the example above to get the same evil and odious results.
<lang python>def pop_kernighan(n):
i = 0
while n:
i, n = i + 1, n & (n - 1)
return i
</lang>
Composition of pure functions
<lang python>Population count
from functools import reduce
- popCount :: Int -> Int
def popCount(n):
The count of non-zero digits in the binary
representation of the positive integer n.
def go(x):
return Just(divmod(x, 2)) if 0 < x else Nothing()
return sum(unfoldl(go)(n))
- -------------------------- TEST --------------------------
def main():
Tests
print('Population count of first 30 powers of 3:')
print(' ' + showList(
[popCount(pow(3, x)) for x in enumFromTo(0)(29)]
))
evilNums, odiousNums = partition(
compose(even, popCount)
)(enumFromTo(0)(59))
print("\nFirst thirty 'evil' numbers:")
print(' ' + showList(evilNums))
print("\nFirst thirty 'odious' numbers:")
print(' ' + showList(odiousNums))
- ------------------------ GENERIC -------------------------
- Just :: a -> Maybe a
def Just(x):
Constructor for an inhabited Maybe (option type) value.
Wrapper containing the result of a computation.
return {'type': 'Maybe', 'Nothing': False, 'Just': x}
- Nothing :: Maybe a
def Nothing():
Constructor for an empty Maybe (option type) value.
Empty wrapper returned where a computation is not possible.
return {'type': 'Maybe', 'Nothing': True}
- compose :: ((a -> a), ...) -> (a -> a)
def compose(*fs):
Composition, from right to left,
of a series of functions.
def go(f, g):
def fg(x):
return f(g(x))
return fg
return reduce(go, fs, lambda x: x)
- enumFromTo :: Int -> Int -> [Int]
def enumFromTo(m):
Enumeration of integer values [m..n] return lambda n: range(m, 1 + n)
- even :: Int -> Bool
def even(x):
True if x is an integer
multiple of two.
return 0 == x % 2
- partition :: (a -> Bool) -> [a] -> ([a], [a])
def partition(p):
The pair of lists of those elements in xs
which respectively do, and don't
satisfy the predicate p.
def go(a, x):
ts, fs = a
return (ts + [x], fs) if p(x) else (ts, fs + [x])
return lambda xs: reduce(go, xs, ([], []))
- showList :: [a] -> String
def showList(xs):
Stringification of a list. return '[' + ','.join(repr(x) for x in xs) + ']'
- unfoldl(lambda x: Just(((x - 1), x)) if 0 != x else Nothing())(10)
- -> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
- unfoldl :: (b -> Maybe (b, a)) -> b -> [a]
def unfoldl(f):
Dual to reduce or foldl.
Where these reduce a list to a summary value, unfoldl
builds a list from a seed value.
Where f returns Just(a, b), a is appended to the list,
and the residual b is used as the argument for the next
application of f.
When f returns Nothing, the completed list is returned.
def go(v):
x, r = v, v
xs = []
while True:
mb = f(x)
if mb.get('Nothing'):
return xs
else:
x, r = mb.get('Just')
xs.insert(0, r)
return xs
return go
- MAIN ---
if __name__ == '__main__':
main()</lang>
- Output:
Population count of first 30 powers of 3:
[1,2,2,4,3,6,6,5,6,8,9,13,10,11,14,15,11,14,14,17,17,20,19,22,16,18,24,30,25,25]
First thirty 'evil' numbers:
[0,3,5,6,9,10,12,15,17,18,20,23,24,27,29,30,33,34,36,39,40,43,45,46,48,51,53,54,57,58]
First thirty 'odious' numbers:
[1,2,4,7,8,11,13,14,16,19,21,22,25,26,28,31,32,35,37,38,41,42,44,47,49,50,52,55,56,59]
Quackery
<lang Quackery> [ 0 swap
[ dup while
dup 1 &
rot + swap
1 >>
again ]
drop ] is popcount ( n --> n )
[ 1 & ] is odd ( n --> b )
[ odd not ] is even ( n --> b )
[ ]'[ temp put 0
[ over while
[ dup popcount
temp share do
if [ dup echo sp
dip [ 1 - ] ]
1+ ]
again ]
2drop temp release ] is echopopwith ( n --> )
say "Population counts of the first thirty powers of 3." cr 30 times [ 3 i^ ** popcount echo sp ] cr cr say "The first thirty evil numbers." cr 30 echopopwith even cr cr say "The first thirty odious numbers." cr 30 echopopwith odd cr</lang>
- Output:
Population counts of the first thirty powers of 3. 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 The first thirty evil numbers. 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 The first thirty odious numbers. 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Racket
<lang racket>#lang racket
- Positive version from "popcount_4" in
- https://en.wikipedia.org/wiki/Hamming_weight#Efficient_implementation
- negative version follows R6RS definition documented in
- http://docs.racket-lang.org/r6rs/r6rs-lib-std/r6rs-lib-Z-H-12.html?q=bitwise-bit#node_idx_1074
(define (population-count n)
(if (negative? n)
(bitwise-not (population-count (bitwise-not n)))
(let inr ((x n) (rv 0))
(if (= x 0) rv (inr (bitwise-and x (sub1 x)) (add1 rv))))))
(define (evil? x)
(and (not (negative? x))
(even? (population-count x))))
(define (odious? x)
(and (positive? x)
(odd? (population-count x))))
(define tasks
(list "display the pop count of the 1st thirty powers of 3 (3^0, 3^1, 3^2, 3^3, 3^4, ...)." (for/list ((i (in-range 30))) (population-count (expt 3 i))) "display the 1st thirty evil numbers." (for/list ((_ (in-range 30)) (e (sequence-filter evil? (in-naturals)))) e) "display the 1st thirty odious numbers." (for/list ((_ (in-range 30)) (o (sequence-filter odious? (in-naturals)))) o)))
(for-each displayln tasks)
(module+ test
(require rackunit) (check-equal? (for/list ((p (sequence-map population-count (in-range 16)))) p) '(0 1 1 2 1 2 2 3 1 2 2 3 2 3 3 4)) (check-true (evil? 0) "0 has just *got* to be evil") (check-true (evil? #b011011011) "six bits... truly evil") (check-false (evil? #b1011011011) "seven bits, that's odd!") (check-true (odious? 1) "the least odious number") (check-true (odious? #b1011011011) "seven (which is odd) bits") (check-false (odious? #b011011011) "six bits... is evil"))</lang>
- Output:
display the pop count of the 1st thirty powers of 3 (3^0, 3^1, 3^2, 3^3, 3^4, ...). (1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25) display the 1st thirty evil numbers. (0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58) display the 1st thirty odious numbers. (1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59)
Raku
(formerly Perl 6) <lang perl6>sub population-count(Int $n where * >= 0) { [+] $n.base(2).comb }
say map &population-count, 3 «**« ^30; say "Evil: ", (grep { population-count($_) %% 2 }, 0 .. *)[^30]; say "Odious: ", (grep { population-count($_) % 2 }, 0 .. *)[^30];</lang>
- Output:
1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 Evil: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 Odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
That's the convenient way to write it, but the following avoids string processing and is therefore about twice as fast: <lang perl6>sub population-count(Int $n is copy where * >= 0) {
loop (my $c = 0; $n; $n +>= 1) {
$c += $n +& 1;
}
$c;
}</lang>
REXX
The pop count is used in some encryption/decryption methods; a major mainframe manufacturer was coerced
(many years ago) to add a hardware instruction to count the bits in a (binary) integer.
<lang rexx>/*REXX program counts the number of "one" bits in the binary version of a decimal number*/
/*─────────────────── and also generates a specific number of EVIL and ODIOUS numbers.*/
parse arg N B . /*get optional arguments from the C.L. */
if N== | N=="," then N= 30 /*N not specified? Then use default. */
if B== | B=="," then B= 3 /*B " " " " " */
numeric digits 2000 /*be able to handle gihugeic numbers.*/
numeric digits max(20, length(B**N) ) /*whittle the precision down to size.*/
$= /* [↑] a little calculation for sizing*/
do j=0 for N; $= $ popCount(B**j) /*generate N popCounts for some powers.*/
end /*j*/ /* [↑] append popCount to the $ list. */
/* [↓] display popCounts of "3" powers*/
call showList 'popCounts of the powers of' B /*display the list with a header/title.*/
do j=0 until #>=N /*generate N evil numbers. */
if popCount(j) // 2 then iterate /*if odd population count, skip it. */
#= # + 1; $= $ j /*bump evil # count; add it to $ list.*/
end /*j*/ /* [↑] build a list of evil numbers. */
/* [↓] display the evil number list. */
call showList 'evil numbers' /*display the $ list with a header. */
do j=0 until #>=N /*generate N odious numbers. */
if popCount(j) // 2 ==0 then iterate /*if even population count, then skip. */
#= # + 1; $=$ j /*bump odious # count; add to $ list. */
end /*j*/ /* [↑] build a list of odious numbers.*/
/* [↓] display the odious number list.*/
call showList 'odious numbers' /*display the $ list with a header. */ exit /*stick a fork in it, we're all done. */ /*──────────────────────────────────────────────────────────────────────────────────────*/ d2b: return word( strip( x2b( d2x( arg(1) ) ), 'L', 0) 0, 1) /*dec ──► bin.*/ popCount: return length( space( translate( d2b(arg(1) ), , 0), 0) ) /*count ones. */ showList: say; say 'The 1st' N arg(1)":"; say strip($); #= 0; $=; return</lang>
- output when using the default input:
The 1st 30 popCounts of the powers of 3: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 The 1st 30 evil numbers: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 The 1st 30 odious numbers: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Ring
<lang ring>
- Project : Population count
load "stdlib.ring" n = 0 neven = 0 nodd = 0 binodd = [] bineven = [] binpow = [] while true
n = n + 1
numb = 0
bin = binarydigits(n)
for nr = 1 to len(bin)
if bin[nr] = "1"
numb = numb + 1
ok
next
if numb % 2 = 0
neven = neven + 1
if neven < 31
add(bineven, n)
ok
else
nodd = nodd + 1
if nodd < 31
add(binodd, n)
ok
ok
if neven > 30 and nodd > 30
exit
ok
end
see "3^x:" + nl for n = 0 to 29
numb = 0
bin = binarydigits(pow(3,n))
for nr = 1 to len(bin)
if bin[nr] = "1"
numb = numb + 1
ok
next
add(binpow, numb)
next showarray(binpow) see nl
see "Evil numbers :" + nl showarray(bineven) see nl see "Odious numbers:" + nl showarray(binodd) see nl
func showarray(vect)
see "["
svect = ""
for n = 1 to len(vect)
svect = svect + vect[n] + ", "
next
svect = left(svect, len(svect) - 2)
see svect
see "]" + nl
</lang> Output:
3^x: [1, 2, 2, 4, 3, 6, 6, 5, 6, 8, 9, 13, 10, 11, 14, 15, 11, 14, 14, 17, 17, 20, 19, 22, 16, 18, 24, 30, 25, 25] Evil numbers : [3, 4, 5, 6, 9, 10, 12, 15, 16, 17, 18, 20, 23, 24, 27, 29, 30, 33, 34, 36, 39, 40, 43, 45, 46, 48, 51, 53, 54, 57] Odious numbers: [1, 2, 7, 8, 11, 13, 14, 19, 21, 22, 25, 26, 28, 31, 32, 35, 37, 38, 41, 42, 44, 47, 49, 50, 52, 55, 56, 59, 61, 62]
Ruby
Demonstrating lazy enumerators. <lang ruby>class Integer
def popcount
digits(2).count(1) #pre Ruby 2.4: self.to_s(2).count("1")
end
def evil?
self >= 0 && popcount.even?
end
end
puts "Powers of 3:", (0...30).map{|n| (3**n).popcount}.join(' ') puts "Evil:" , 0.step.lazy.select(&:evil?).first(30).join(' ') puts "Odious:", 0.step.lazy.reject(&:evil?).first(30).join(' ')</lang>
- Output:
Powers of 3: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 Evil: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 Odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Rust
<lang Rust>fn main() {
let mut num = 1u64;
let mut vec = Vec::new();
for _ in 0..30 {
vec.push(num.count_ones());
num *= 3;
}
println!("pop count of 3^0, 3^1 ... 3^29:\n{:?}",vec);
let mut even = Vec::new();
let mut odd = Vec::new();
num = 1;
while even.len() < 30 || odd.len() < 30 {
match 0 == num.count_ones()%2 {
true if even.len() < 30 => even.push(num),
false if odd.len() < 30 => odd.push(num),
_ => {}
}
num += 1;
}
println!("\nFirst 30 even pop count:\n{:?}",even);
println!("\nFirst 30 odd pop count:\n{:?}",odd);
}</lang>
- Output:
pop count of 3^0, 3^1 ... 3^29: [1, 2, 2, 4, 3, 6, 6, 5, 6, 8, 9, 13, 10, 11, 14, 15, 11, 14, 14, 17, 17, 20, 19, 22, 16, 18, 24, 30, 25, 25] First 30 even pop count: [3, 5, 6, 9, 10, 12, 15, 17, 18, 20, 23, 24, 27, 29, 30, 33, 34, 36, 39, 40, 43, 45, 46, 48, 51, 53, 54, 57, 58, 60] First 30 odd pop count: [1, 2, 4, 7, 8, 11, 13, 14, 16, 19, 21, 22, 25, 26, 28, 31, 32, 35, 37, 38, 41, 42, 44, 47, 49, 50, 52, 55, 56, 59]
Scala
- Output:
See it yourself by running in your browser either by ScalaFiddle (ES aka JavaScript, non JVM) or Scastie (remote JVM).
<lang Scala>import java.lang.Long.bitCount
object PopCount extends App {
val nNumber = 30
def powersThree(start: Long): LazyList[Long] = start #:: powersThree(start * 3L)
println("Population count of 3ⁿ :")
println(powersThree(1L).map(bitCount).take(nNumber).mkString(", "))
def series(start: Long): LazyList[Long] = start #:: series(start + 1L)
println("Evil numbers:")
println(series(0L).filter(bitCount(_) % 2 == 0).take(nNumber).mkString(", "))
println("Odious numbers:")
println(series(0L).filter(bitCount(_) % 2 != 0).take(nNumber).mkString(", "))
}</lang>
Seed7
The function popcount below converts
the integer into a bitset.
The function card
is used to compute the population count of the bitset.
<lang seed7>$ include "seed7_05.s7i";
const func integer: popcount (in integer: n) is
return card(bitset(n));
const proc: main is func
local
var integer: count is 0;
var integer: num is 0;
begin
for num range 0 to 29 do
write(popcount(3 ** num) <& " ");
end for;
writeln;
write("evil: ");
for num range 0 to integer.last until count >= 30 do
if not odd(popcount(num)) then
write(num <& " ");
incr(count);
end if;
end for;
writeln;
write("odious: ");
count := 0;
for num range 0 to integer.last until count >= 30 do
if odd(popcount(num)) then
write(num <& " ");
incr(count);
end if;
end for;
writeln;
end func;</lang>
- Output:
1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 evil: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Sidef
<lang ruby>func population_count(n) { n.as_bin.count('1') } say "#{0..29 «**« 3 «call« population_count -> join(' ')}" var numbers = 60.of { |i|
[i, population_count(i)]
} say "Evil: #{numbers.grep{_[1] %% 2}.map{.first}.join(' ')}" say "Odious: #{numbers.grep{_[1] & 1}.map{.first}.join(' ')}"</lang>
- Output:
1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 Evil: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 Odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Swift
<lang swift>func populationCount(n: Int) -> Int {
guard n >= 0 else { fatalError() }
return String(n, radix: 2).filter({ $0 == "1" }).count
}
let pows = (0...)
.lazy
.map({ Int(pow(3, Double($0))) })
.map(populationCount)
.prefix(30)
let evils = (0...)
.lazy
.filter({ populationCount(n: $0) & 1 == 0 })
.prefix(30)
let odious = (0...)
.lazy
.filter({ populationCount(n: $0) & 1 == 1 })
.prefix(30)
print("Powers:", Array(pows)) print("Evils:", Array(evils)) print("Odious:", Array(odious))</lang>
- Output:
Powers: [1, 2, 2, 4, 3, 6, 6, 5, 6, 8, 9, 13, 10, 11, 14, 15, 11, 14, 14, 17, 17, 20, 19, 22, 16, 18, 24, 30, 25, 25] Evils: [0, 3, 5, 6, 9, 10, 12, 15, 17, 18, 20, 23, 24, 27, 29, 30, 33, 34, 36, 39, 40, 43, 45, 46, 48, 51, 53, 54, 57, 58] Odious: [1, 2, 4, 7, 8, 11, 13, 14, 16, 19, 21, 22, 25, 26, 28, 31, 32, 35, 37, 38, 41, 42, 44, 47, 49, 50, 52, 55, 56, 59]
Symsyn
<lang Symsyn>
| Pop Count 3^i
i if i < 30 (3^i) x popcount x 63 x ~ x $r + $r $s + ' ' $s + i goif endif "' Pop Count 3^i : ' $s " []
| Evil Numbers
i
cnt
if cnt < 30
popcount i 7 x
x:0:1 y
if y <> 1
+ cnt
~ i $r
+ $r $e
+ ' ' $e
endif
+ i
goif
endif
"' Evil Numbers : ' $e " []
| Odious Numbers
i
cnt
if cnt < 30
popcount i 7 x
x:0:1 y
if y = 1
+ cnt
~ i $r
+ $r $o
+ ' ' $o
endif
+ i
goif
endif
"' Odious Numbers : ' $o " []
</lang>
- Output:
Pop Count 3^i : 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 Evil Numbers : 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 Odious Numbers : 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Tcl
<lang tcl>package require Tcl 8.6
proc hammingWeight {n} {
tcl::mathop::+ {*}[split [format %llb $n] ""]
} for {set n 0;set l {}} {$n<30} {incr n} {
lappend l [hammingWeight [expr {3**$n}]]
} puts "p3: $l" for {set n 0;set e [set o {}]} {[llength $e]<30||[llength $o]<30} {incr n} {
lappend [expr {[hammingWeight $n]&1 ? "o" : "e"}] $n
} puts "evil: [lrange $e 0 29]" puts "odious: [lrange $o 0 29]"</lang>
- Output:
p3: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 evil: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
UNIX Shell
<lang bash>popcount() {
local -i n=$1
(( n < 0 )) && return 1
local ones=0
while (( n > 0 )); do
(( ones += n%2 ))
(( n /= 2 ))
done
echo $ones
}
popcount_3s=() n=1 for (( i=0; i<30; i++ )); do
popcount_3s+=( $(popcount $n) ) (( n *= 3 ))
done echo "powers of 3 popcounts: ${popcount_3s[*]}"
evil=() odious=() n=0 while (( ${#evil[@]} < 30 || ${#odious[@]} < 30 )); do
p=$( popcount $n )
if (( $p%2 == 0 )); then
evil+=( $n )
else
odious+=( $n )
fi
(( n++ ))
done echo "evil nums: ${evil[*]:0:30}" echo "odious nums: ${odious[*]:0:30}"</lang>
- Output:
powers of 3 popcounts: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 evil nums: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 odious nums: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
VBA
The Decimal subtype of Variant does the job to expand 32-bit integers (Long) to 28-digit integers (Decimal). <lang vb>Sub Population_count()
nmax = 30
b = 3
n = 0: List = "": bb = 1
For i = 0 To nmax - 1
List = List & " " & popcount(bb)
bb = bb * b
Next 'i
Debug.Print "popcounts of the powers of " & b
Debug.Print List
For j = 0 To 1
If j = 0 Then c = "evil numbers" Else c = "odious numbers"
n = 0: List = "": i = 0
While n < nmax
If (popcount(i) Mod 2) = j Then
n = n + 1
List = List & " " & i
End If
i = i + 1
Wend
Debug.Print c
Debug.Print List
Next 'j
End Sub 'Population_count
Private Function popcount(x)
Dim y, xx, xq, xr
xx = x
While xx > 0
xq = Int(xx / 2)
xr = xx - xq * 2
If xr = 1 Then y = y + 1
xx = xq
Wend
popcount = y
End Function 'popcount </lang>
- Output:
popcounts of the powers of 3: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 evil numbers: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 odious numbers: ' 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
VBScript
Use of the variant currency subtype. Currency mode is a gray area where some operators do not work, for instance: ^ \ Mod <lang vb>' Population count - VBScript - 10/05/2019 nmax=30 b=3 n=0: list="": bb=1 For i=0 To nmax-1 list=list & " " & popcount(bb) bb=bb*b Next 'i Msgbox list,,"popcounts of the powers of " & b For j=0 to 1 If j=0 Then c="evil numbers": Else c="odious numbers" n=0: list="": i=0 While n<nmax If (popcount(i) Mod 2)=j Then n=n+1 list=list & " " & i End If i=i+1 Wend Msgbox list,,c Next 'j
Function popcount(x) Dim y,xx,xq,xr xx=x While xx>0 xq=Int(xx/2) xr=xx-xq*2 If xr=1 Then y=y+1 xx=xq Wend popcount=y End Function 'popcount </lang>
- Output:
popcounts of the powers of 3: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 evil numbers: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 odious numbers: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Visual Basic .NET
<lang vbnet>Imports System.Console, System.Diagnostics
Module Module1
Dim i As Integer, eo As Boolean
Function PopCnt(n As Long) As Integer Return Convert.ToString(n, 2).ToCharArray().Where(Function(x) x = "1").Count() End Function
Sub Aline(a As List(Of Integer), title As String)
WriteLine("{0,-8}{1}", title, String.Join(" ", a.Take(30)))
End Sub
Sub Main(ByVal args As String())
WriteLine("Population Counts:") : Dim t, e, o As New List(Of Integer)
For c As Integer = 0 To 99
If (PopCnt(c) And 1) = 0 Then e.Add(c) Else o.Add(c)
If c < 30 Then t.Add(PopCnt(CLng(Math.Pow(3, c))))
Next
Aline(t, "3^n :") : Aline(e, "Evil:") : Aline(o, "Odious:")
' Extra:
WriteLine(vbLf & "Pattern:{0}", Pattern(e, o))
If Debugger.IsAttached Then ReadKey()
End Sub
' support routines for pattern output Function Same(a As List(Of Integer)) As Boolean Return a(i) + 1 = a(i + 1) End Function
Function Odd(a As List (Of Integer), b As List (Of Integer)) As Boolean eo = Not eo : If a(i) = b(i) + 1 Then i -= 1 : Return True Return False End Function
Function SoO(a As List (Of Integer), b As List (Of Integer), c As String) As String Return If(Same(a), c(0), If(Odd(b, a), c(1), c(2))) End Function
Function Either(a As List(Of Integer), b As List(Of Integer)) As String Return If(eo, SoO(a, b, "⌢↓↘"), SoO(b, a, "⌣↑↗")) End Function
Function Pattern(a As List(Of Integer), b As List(Of Integer)) As String eo = a.Contains(0) : Dim res As New Text.StringBuilder For i = 0 To a.Count - 2 : res.Append(Either(a, b)) : Next Return res.ToString() End Function
End Module</lang>
- Output:
Added a "Pattern" line. The "Pattern" line shows the sequence pattern of integers for the Evil and Odious output. The pattern goes to about 50, whereas only the first 30 Evil and Odious integers are shown.
Population Counts: 3^n : 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 Evil: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 Odious: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59 Pattern:↓⌣↑↘↑⌢↓⌣↑⌢↓↗↓⌣↑↘↑⌢↓↗↓⌣↑⌢↓⌣↑↘↑⌢↓⌣↑⌢↓↗↓⌣↑⌢↓⌣↑↘↑⌢↓↗↓⌣↑↘↑⌢↓⌣↑⌢↓↗↓⌣↑↘↑⌢↓↗↓⌣↑⌢↓⌣↑↘↑⌢↓↗↓⌣↑↘↑⌢↓⌣↑⌢↓↗↓⌣↑⌢↓⌣
P.S., The Pattern line may not appear properly on some browsers.
Wren
The first part is slightly awkward for Wren as 'native' bit-wise operations are limited to unsigned 32-bit integers and 3^21 exceeds this limit. We therefore need to switch to BigInts just before that point to process the remaining powers. <lang ecmascript>import "/big" for BigInt import "/fmt" for Fmt
var popCount = Fn.new { |n|
var count = 0
while (n != 0) {
n = n & (n - 1)
count = count + 1
}
return count
}
System.print("The population count of the first 30 powers of 3 is:") var p3 = 1 for (i in 0..29) {
System.write("%(popCount.call(p3)) ")
p3 = p3 * 3
if (i == 20) p3 = BigInt.new(p3)
} var odious = [] System.print("\n\nThe first 30 evil numbers are:") var count = 0 var n = 0 while (count < 30) {
var pc = popCount.call(n)
if (pc%2 == 0) {
System.write("%(n) ")
count = count + 1
} else {
odious.add(n)
}
n = n + 1
} odious.add(n) System.print("\n\nThe first 30 odious numbers are:") Fmt.print("$d", odious)</lang>
- Output:
The population count of the first 30 powers of 3 is: 1 2 2 4 3 6 6 5 6 8 9 13 10 11 14 15 11 14 14 17 17 20 19 22 16 18 24 30 25 25 The first 30 evil numbers are: 0 3 5 6 9 10 12 15 17 18 20 23 24 27 29 30 33 34 36 39 40 43 45 46 48 51 53 54 57 58 The first 30 odious numbers are: 1 2 4 7 8 11 13 14 16 19 21 22 25 26 28 31 32 35 37 38 41 42 44 47 49 50 52 55 56 59
Yabasic
<lang Yabasic>print "Pop count (3^x): "
for i = 0 to 29
print population(3^i);
next print "\n"
print "Evil: " EvilOdious(30) print "\n"
print "Odious: " EvilOdious(30, 1) print "\n"
sub EvilOdious(limit, type)
local i, count, eo
repeat
eo = mod(population(i), 2)
if (type and eo) or (not type and not eo) count = count + 1 : print i;
i = i + 1
until(count = limit)
end sub
sub population(number)
local i, binary$, popul
binary$ = bin$(number)
for i = 1 to len(binary$)
popul = popul + val(mid$(binary$, i, 1))
next
return popul
end sub</lang>
zkl
Ints have the 1s count as a property. <lang zkl>n:=1; do(30){ print(n.num1s,","); n*=3 } println();
println("evil: ",[0..].filter(30,fcn(n){ n.num1s.isEven }).concat(","));
// now, as an iterator aka lazy: println("odious: ",(0).walker(*).tweak( // 0,1,2,3,4... iterator
fcn(n){ if(n.num1s.isEven) Void.Skip else n }).walk(30).concat(","));</lang>
- Output:
1,2,2,4,3,6,6,5,6,8,9,13,10,11,14,15,11,14,14,17,17,20,19,22,16,18,24,30,25,25, evil: 0,3,5,6,9,10,12,15,17,18,20,23,24,27,29,30,33,34,36,39,40,43,45,46,48,51,53,54,57,58 odious: 1,2,4,7,8,11,13,14,16,19,21,22,25,26,28,31,32,35,37,38,41,42,44,47,49,50,52,55,56,59
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