Complement of base 10 integer

Bit Manipulation

60.6% acceptance

Feb 25, 2026

2594

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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 n, return its complement.

Solution

Rust

Time O(n)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn bitwise_complement(n: i32) -> i32 {
    if n == 0 { return 1; }
    let mut mask = 1i32;
    while mask <= n { mask <<= 1; }
    (mask - 1) ^ n
  }
}