[leetcode]Bit Manipulation-476. Number Complement

最新推荐文章于 2018-10-08 14:18:40 发布

转载最新推荐文章于 2018-10-08 14:18:40 发布 · 68 阅读

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原文链接：http://www.cnblogs.com/chenhan05/p/8280237.html

本文介绍了一种求解正整数补码的方法，并提供了一个C++实现示例。通过翻转输入整数的二进制表示来计算其补码。文章包含两个示例：输入5时输出2，输入1时输出0。

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

Note:

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

Example 1:

Input: 5
Output: 2
Explanation: The binary representation of 5 is 101 (no leading zero bits), and its complement is 010. So you need to output 2.

Example 2:

Input: 1
Output: 0
Explanation: The binary representation of 1 is 1 (no leading zero bits), and its complement is 0. So you need to output 0.

class Solution {
    public:
        int findComplement(int num) {
            long int flag = 1;
            long int res = 0;
            while(flag && flag <= num){
                int t = flag&num;
                if(t == 0){
                    res |= flag;
                }

                flag = flag << 1;
            }
            return res;
        }
    };

转载于:https://www.cnblogs.com/chenhan05/p/8280237.html