Leetcode 476. Number Complement

Tyan

发布于 2019-05-25 22:59:41

3320

发布于 2019-05-25 22:59:41

文章被收录于专栏：SnailTyanSnailTyan

文章作者：Tyan

博客：noahsnail.com | CSDN | 简书

1. Description

2. Solution

Version 1

class Solution {
public:
    int findComplement(int num) {
        int result = 0;
        stack<int> s;
        while(num) {
            int bit = num & 1;
            num >>= 1;
            s.push(bit);
        }
        while(!s.empty()) {
            result <<= 1;
            int bit = s.top();
            s.pop();
            result |= (bit ^ 1);
        }
        return result;
    }
};

Version 2

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