Minimum operations to make binary palindrome

Array Two Pointers Binary Search Bit Manipulation

51.6% acceptance

Feb 25, 2026

You are given an integer array nums. For each element nums[i], you may perform the following operations any number of times (including zero): Increase nums[i] by 1, or Decrease nums[i] by 1. A number is called a binary palindrome if its binary representation without leading zeros reads the same forward and backward. Your task is to return an integer array ans, where ans[i] represents the minimum number of operations required to convert nums[i] into a binary palindrome.

Solution

Rust

Time O(2^n)

Space O(n)

LeetCode

solution.rs

impl Solution {
  pub fn min_operations(nums: Vec<i32>) -> Vec<i32> {
    fn is_bin_palindrome(n: i32) -> bool {
      let bits: Vec<u8> = format!("{:b}", n).bytes().collect();
      let len = bits.len();
      (0..len / 2).all(|i| bits[i] == bits[len - 1 - i])
    }
    nums.iter().map(|&n| {
      if is_bin_palindrome(n) { return 0; }
      let mut d = 1i32;
      loop {
        if n - d >= 1 && is_bin_palindrome(n - d) { return d; }
        if is_bin_palindrome(n + d) { return d; }
        d += 1;
      }
    }).collect()
  }
}