2017/11/5 Leetcode 日记

2017/11/5 Leetcode 日记

 

476. Number Complement

Given a positive integer, output its complement number. The complement strategy is to flip the bits of its binary representation.

Note:

1. The given integer is guaranteed to fit within the range of a 32-bit signed integer.
2. You could assume no leading zero bit in the integer’s binary representation.

Solutions:

class Solution {
public:
    int findComplement(int num) {
        unsigned mask = ~0;
        while(mask & num) mask <<=1;
        return ~mask & ~num;
    }
};

c++