求32位整数二进制1的个数收藏

【摘自编程之美】

#include <iostream>
using namespace std;

int findone(unsigned int n)
{
    int i;
    for(i=0; n>0; n>>=1)
        i+=(n&1);
    return i;
}

int func(unsigned int n)
{
    int count=0;
    while(n>0)
    {
        n&=(n-1);
        count++;
    }
    return count;
}

int main()
{
    int n;
    cin >> n;
    cout << findone(n) << endl;
    cout << func(n) << endl;
    return 0;
}