Algorithm3: 获得一个int数中二进制位为1 的个数

获得一个int数中二进制位为1 的个数

 

int NumberOfOne(int n){

                 int count = 0;

                 unsigned int flag = 1;

                 while (flag){

                                 if (n & flag){

                                                count++;

                                }

                                flag = flag << 1;

                }

                 return count;

}

int NumberOfOne2(int n){

                 int count = 0;

                 while (n )

                {

                                count++;

                                 n = n &(n - 1);

                }

                 return count;

}