Number complement

Bit Manipulation

70.4% acceptance

Jan 13, 2026

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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.

Solution

Rust

Time O(1)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn find_complement(num: i32) -> i32 {
    let bits = 32 - num.leading_zeros();
    let mask = (1 << bits) - 1;
    num ^ mask
  }
}