[leetcode] 476. Number Complement @ python

最新推荐文章于 2025-02-21 14:04:07 发布

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本文详细解析了如何通过转换十进制整数到二进制，再反转其二进制位，最后将反转后的二进制转回十进制来求得一个正整数的补数。此算法适用于32位有符号整数范围内的输入，并假设没有前导零。

原题

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.

解法

十进制转二进制, 然后对二进制的字符’1’变为’0’, ‘0’变为’1’, 最后转为十进制

代码

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