Given a positive integer, output its complement number. The complement strategy is to flip the bits of its 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.
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.
- This question is the same as 1009: https://leetcode.com/problems/complement-of-base-10-integer/
A:
就是简单的位运算class Solution { public: int findComplement(int num) { int res = 0; for(int i =0;i<32 and num>0;++i) { int tmp = num & (1<<i); if(tmp==0){ res += 1<<i; }else{ num -= tmp; } } return res; } };
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