求给定整数中二进制数1的个数

#include <iostream>

using namespace std;

int countx(int x)

{

    int count= 0;

    while(x)

    {

        x = x&(x-1);

        count++;

    }

    return count;

}

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

{

    cout<<countx(7)<<endl;

    return 0;

}