The problem
Given a positive integer num
, output its complement number. The complement strategy is to flip the bits of its binary representation.
Example 1:
Input: num = 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: num = 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.
Constraints:
- The given integer
num
is guaranteed to fit within the range of a 32-bit signed integer. num >= 1
- You could assume no leading zero bit in the integer’s binary representation.
The code
// Our method that takes in an `int` and returns an `int` public int findComplement(int num) { // Duplicate the input for reference int originalNum = num; // Set a variable for looping on an index long i = 1; // Loop while `i` is less or equal to `originalNum` while(i<=originalNum) { // Shift the variables num ^= i; i <<= 1; } // Return the resultant `num` return num; }