给定一个整数，求它的二进制表示中有多少个1。

 1 #include<stdio.h>

int countOne( int n )
{
    int count = 0;
    while( n != 0 )
    {
        n &= n - 1;
        ++count;
    }
    return count;
}

int main()
{
    int num;
    printf("Input the number : ");
    scanf( "%d", &num );
    printf( "The number of binary one is %d.\n", countOne(num) );
    return 0;
}