剑指offer 11：二进制中1的个数

class Solution {
public:
     int  NumberOf1(int n) {
         unsigned int flag=1;
         int count=0;
         while(flag!=0){
             if(n&flag){
                 count++;
             }
             flag=flag<<1;
         }
         return count;
     }
};

class Solution {
public:
     int  NumberOf1(int n) {
         int count=0;
         while(n!=0){
              count++;
              n = n & (n-1);   
          }
         return count;
     }
};