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.
Companies:
Cloudera
Related Topics:
Bit Manipulation
For example:
num = 00000101
mask = 11111000
~mask & ~num = 00000010
// OJ: https://leetcode.com/problems/number-complement/
// Author: github.com/lzl124631x
// Time: O(1)
// Space: O(1)
class Solution {
public:
int findComplement(int num) {
unsigned mask = ~0;
while (num & mask) mask <<= 1;
return ~mask & ~num;
}
};