Find the number of 1 in a binary binary (optimized). Determine if a number is 2 of the n-th square

Find the number of 1 in a binary binary:

General Method :

#include <stdio.h>

#include <stdlib.h>

int count_one_bits (unsigned int value)

{

int count = 0;

for (int i = 0; i <; i++)

{

if      (value & 1 = = 1) (%2 equivalent to &1)

{

count++;

}

value = value >> 1; (move right one equivalent to 2)

}

return count;

}

int Main ()

{

unsigned int value= 0;

scanf ( "%d" , &value);

int ret = count_one_bits (value);

printf ( "%d\n" , ret);

System ( "pause" );

return 0;

}

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Optimization:

#include <stdio.h>

#include <stdlib.h>

int count_one_bits (unsigned int value)

{

int count = 0;

while (value )//value enters a loop if nonzero

{

count++; Because value is not 0, there is at least one 1 in the binary

value = value & (value -1); N and n& (n-1) binary is always a difference of 1

}

return count;

}

int Main ()

{

unsigned int value= 0;

scanf ( "%d", &value);

int ret = count_one_bits (value);

printf ( "%d\n", ret);

System ( "pause");

return 0;

}

To ask a number of books is not 2 of the n-th square:

#include <stdio.h>

int main ()

{

int num=0;

scanf ("%d", &num);          

if (value & (value -1)) ==0);

printf ("yes\n");

Else

printf ("no\n");

return 0;

}

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Find the number of 1 in a binary binary (optimized). Determine if a number is 2 of the n-th square