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)