LeetCode 476. Number Complement

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题目

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

Example 1:

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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:

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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.

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.
  3. This question is the same as 1009.

思路

Easy题，按题目要求操作即可，没什么好说的打个卡而已。。。

代码

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class Solution(object):
    def findComplement(self, num):
        """
        :type num: int
        :rtype: int
        """
        bin_num = bin(num)[2:]
        ans = ''.join([str(1-int(i)) for i in bin_num])
        return int(ans, 2)