Here are four C programs that count the bits on in an integer; that is$,$ you run $\text{'}./$cb $5\text{'}$ and it will print $\text{'}2\text{'}($because $5$ in binary is $101,$ and two bits are turned on$).$ For each

program, indicate whether it works. If it does not, show how to fix it by changing the fewest characters possible. Note that these programs will crash if not given an argument; that's not considered an error per the design spec.

Program A

Works as is$.$

Needs fixing.

#include

#include

int main$($int arge, char $*$argv$[])$

$\{$

$//$ warning: assumes argv$[1]!$

int val $=$ atoi$($argv$[1])$;

int sum $=0$;

for $($int i $=0$; i $<mtext></mtext><mn>3</mn><mn>2</mn>$; i$++)$

if $(1$ i $*$ val$)$

sum $+=1$;

printf$("\%$d

$",$ sum$)$;

$\}$

Program B

Works as is$.$

Needs fixing.

#include

#include

int main$($int argc, char $*$argv$[])$

$\{$

$//$ warning: assumes argv$[1]!$

int val $=$ atoi$($argv$[1])$;

int sum $=0$;

for $($int i $=31$; i $>=0$; i$--)$

if $((1$ i$)$ & val$)$

sum $+=1$;

printf$("\%$d

$",$ sum$)$;

$\}$

Program C

Works as is$.$ Needs fixing.

#include

#include

int main$($int argc, char $*$argv$[])$

$\{$

$//$ warning: assumes argv$[1]!$

int val $=$ atoi$($argv$[1])$;

int sum $=0$;

while $($ val $)\{$

if $($ val $>0)$

sum $++$;

val $<mtext></mtext><mn>1</mn>$;

$\}$

printf$("\%$d

$",$ val$)$;

$\}$

Program D

Works as is$.$ Needs fixing.

#include

#include

int main$($int argc, char $*$argv$[])$

$\{$

$//$ warning: assumes argv$[1]!$

int val $=$ strtoul$($argv$[1],$ NULL, $10)$;

int sum $=0$;

while $($val$)\{$

sum $=$ val & $1$;

val $>=1$;

$\}$

printf$("\%$d $//$n$",$ sum$)$;

$\}$