求一个数的二进制数中的1的个数

#include<stdio.h>

int main()

{

int num = -1, count = 0;

while (num)

{

count++;

num = num&(num - 1);

}

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

system("pause");

return 0;

}

用函数编写

#include<stdio.h>

int count_one_bit(num)

{

int count = 0;

while (num)

{

count++;

num = num&(num - 1);

}

return count;

}

int main()

{

int num = -1;

int ret = count_one_bit(num);

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

system("pause");

return 0;

}