Minimum number of flips to reverse binary string

Math Two Pointers String Bit Manipulation

75.8% acceptance

Feb 25, 2026

You are given a positive integer n. Let s be the binary representation of n without leading zeros. The reverse of a binary string s is obtained by writing the characters of s in the opposite order. You may flip any bit in s (change 0 → 1 or 1 → 0). Each flip affects exactly one bit. Return the minimum number of flips required to make s equal to the reverse of its original form.

Solution

Rust

Time O(n)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn minimum_flips(n: i32) -> i32 {
    let bits: Vec<u8> = format!("{:b}", n).bytes().map(|b| b - b'0').collect();
    let len = bits.len();
    (0..len).filter(|&i| bits[i] != bits[len - 1 - i]).count() as i32
  }
}