476 Number Complement

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.
  • This question is the same as 1009
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func findComplement(num int) int {
	result := 0
	power := 1
	for num > 0 {
		result += (num % 2 ^ 1) * power
		power <<= 1
		num >>= 1
	}
	return result
}