LeetCode- 476 Number Complement(easy)

题目：

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

　　　Note:

1. 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.

　　　Example 1:

Input: 5Output: 2Explanation: The binary representation of 5 is 101 (no leading zero bits), and its complement is 010. So you need to output 2.

 

代码：

 1 class Solution { 2 public: 3     int findComplement(int num) { 4         int x = 0, p = 0; 5         while(num){ 6             if(num%2==0) x |= (1 << p); 7             ++p; 8             num/=2; 9         }10         return x;11     }12 };