Number Complement

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.

Github: code.dennyzhang.com

Credits To: leetcode.com

Leave me comments, if you have better ways to solve.

## https://code.dennyzhang.com/number-complement class Solution(object): def findComplement(self, num): """ :type num: int :rtype: int """ i = num ret = 0 digit_count = 0 while i != 0: reverse_current_digit = 1 ^ (i % 2) ret = (reverse_current_digit << digit_count) | ret digit_count = digit_count + 1 i = i >> 1 # print("i: %i, ret: %d, digit_count: %d, reverse_current_digit: %d", i, ret, digit_count, reverse_current_digit) return ret if __name__ == '__main__': s = Solution() print s.findComplement(5) # 2 print s.findComplement(3) # 0 print s.findComplement(1) # 0