Leetcode-Algorithms Number Complement(数字补码）

2019-11-08 02:08:08

字体：大中小

来源：转载

供稿：网友

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.

如题数字补码就是求本身的补码后return其十进制的数。二进制5 = 101（无视正负位的数->leading bit）其补码 010 = 2

class Solution(object): def findComplement(self, num): """ :type num: int :rtype: int """ return (1<<len("{0:b}".format(num)))-1 ^ num

首先将补位到和二进制带leading bits的num相同长度（10000…..）， -1后用^运算符补码.

上一篇：AtCoder Regular Contest 069 D - Menagerie 枚举起点递推

下一篇：PAT A 1001. A+B Format (20)