#include

    int bit_count(unsigned int n)

    {

    int count;

    for(count = 0; n; n=n &(n - 1))

    {

    count++;

    }

    return count;

    }

    int main()

    { int k;

    int num;

    printf("輸入一個數(shù)：");

    scanf("%d",&num);

    k=bit_count(num);

    printf("1的個數(shù)為%d\n",k);

    return 0;

    }