How to count the ones in a binary representation of a given hex in a cmd Batch? - batch-file

Question

i am trying to write a batch file that asks the user to type a hexadcimal number and then counts the number of ones in the binary representation , like if i typed A the program echos 1 .
i have this code that uses a look up table to convert from binary to hex and answered by Aacini here ...
#echo off
setlocal
set "bin=110111101010110110111110111011111100101011111110"
call :bin2hex hex=%bin%
echo hex: %hex%
goto :EOF
:bin2hex hexVar=binValue
setlocal EnableDelayedExpansion
for %%a in (0000-0;0001-1;0010-2;0011-3;0100-4;0101-5;0110-6;0111-7;1000-8;1001-9;1010-A;1011-B;1100-C;1101-D;1110-E;1111-F) do (
for /F "tokens=1,2 delims=-" %%b in ("%%a") do (
set "hextable[%%b]=%%c"
)
)
set "hex="
set "bin=000%~2"
:bin2hexloop
set "hex=!hextable[%bin:~-4%]!%hex%"
set "bin=%bin:~0,-4%"
if defined bin if "%bin:~3%" neq "" goto bin2hexloop
endlocal & set "%~1=%hex%"
goto :EOF
i tried to inverse the way this code works , but it didn't work !
here is my attempt
#echo off
setlocal
set "hex=ABCDEF"
call :hex2bin bin=%bin%
echo : %bin%
pause;
goto :EOF
:hex2bin binVar=hexValue
setlocal EnableDelayedExpansion
for %%a in (0-0000;1-0001;2-0010;3-0011;4-0100;5-0101;6-0110;7-0111;8-1000;9-1001;A-1010;B-1011;C-1100;D-1101;E-1110;F-1111) do (
for /F "tokens=1,2 delims=-" %%b in ("%%a") do (
set "bintable[%%b]=%%c"
)
)
set "bin="
set "hex=000%~16"
:hex2binloop
set "bin=!bintable[%hex:~-4%]!%bin%"
set "hex=%hex:~0,-4%"
if defined hex if "%hex:~3%" neq "" goto hex2binloop
endlocal & set "%~4=%bin%"
goto :EOF
anybody can help me ?

Answer 1

If I understood you correctly, you want not to "convert a hexadecimal number to binary", but to "count the ones that each hex digit have" and accumulate they (for example, for A the number is 1). This way, the solution must work with "The number of ones each hex digit have".
#echo off
setlocal
set "hex=ABCDEF"
call :countOnesInHex ones=%hex%
echo There are %ones% ones in %hex%
pause
goto :EOF
:countOnesInHex ones=hexValue
setlocal
for %%a in (0-0;1-1;2-1;3-2;4-1;5-2;6-2;7-3;8-1;9-2;A-2;B-3;C-2;D-3;E-3;F-4) do (
for /F "tokens=1,2 delims=-" %%b in ("%%a") do (
set "onesIn[%%b]=%%c"
)
)
set ones=0
set "hex=%~2"
:hexCountLoop
set /A ones+=onesIn[%hex:~0,1%]
set "hex=%hex:~1%"
if defined hex goto hexCountLoop
endlocal & set "%1=%ones%"
exit /B

Answer 2

Convert the number to decimal and do the basic math: divide by 2 and sum the remainders.
Do it in chunks of 7 hexadecimal digits because batch file calculations support only 31 bits (2^31-1 or 2147483647 or 0x7FFFFFFF).
set hex=ABCDEFABCDEFABCDEF
set ones=0
:loopchunks
set /a decimal=0x%hex:~0,7%
set hex=%hex:~7%
:loopdigits
set /a ones+=decimal %% 2, decimal/=2
if not %decimal%==0 goto loopdigits
if defined hex goto loopchunks
echo %ones%
Output:
51

Answer 3

#ECHO OFF
SETLOCAL
FOR %%a IN (F37ABD abcdef 123 321 99 100 f11f 0 cafe) DO CALL :mainproc %%a
GOTO :eof
:mainproc
SET hexnum=%1
SET /a count1=0
:loop
SET /a hex1=0x%hexnum:~0,1%
:bitloop
SET /a count1+=%hex1% %% 2
SET /a hex1/=2
IF %hex1% gtr 0 GOTO bitloop
SET hexnum=%hexnum:~1%
IF DEFINED hexnum GOTO loop
ECHO %count1% 1s detected IN %1
GOTO :EOF
The for loop simply assigns the values in the list to the variable %%a in turn and executes the main part of the procedure with a parameter (%1) of that item.
Within the main procedure, initialise hexnum as the number to be analysed and count1 with the accumulated number of 1s
Then set hex1 to 0xstrung before (copy the first digit of hexnum) which will be a hex numeric, 0x0 to 0xf. SInce this is the format for cmd to accept a hex number, it sets hex1 to decimal 0..15
next add (hex1 mod 2) to count, that is 1 or zero if odd/even
next halve hex1. Since cmd calculates in integer mode, the result is truncated, hence 6=>3 and 7+>3
the result is >0, do the next binary digit. repeat until 0.
Toss out the first character of hexnum (assign the substring starting at character 1, given that it starts counting at "character 0")
If hexnum has characters left, repeat for the next hex digit
otherwise, report.
result:
17 1s detected IN F37ABD
17 1s detected IN abcdef
4 1s detected IN 123
4 1s detected IN 321
4 1s detected IN 99
1 1s detected IN 100
10 1s detected IN f11f
0 1s detected IN 0
11 1s detected IN cafe