476. Number Complement #

Problem Statement #

The complement of an integer is the integer you get when you flip all the 0's to 1's and all the 1's to 0's in its binary representation.

• For example, The integer 5 is "101" in binary and its complement is "010" which is the integer 2.

Given an integer num, return its complement.

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:

• 1 <= num < 231

Note: This question is the same as 1009: https://leetcode.com/problems/complement-of-base-10-integer/

Solution: #

impl Solution {
    pub fn find_complement(num: i32) -> i32 {
        let mut res = String::default();

        for ch in format!("{:b}", num).chars() {
            if ch == '0' {
                res += "1";
            } else {
                res += "0";
            }
        }

        i32::from_str_radix(&res, 2).unwrap()
    }
}

... #