Minimum operations to equalize array

Array Bit Manipulation Brainteaser

60.1% acceptance

Feb 25, 2026

You are given an integer array nums of length n. In one operation, choose any subarray nums[l...r] (0 <= l <= r < n) and replace each element in that subarray with the bitwise AND of all elements. Return the minimum number of operations required to make all elements of nums equal. A subarray is a contiguous non-empty sequence of elements within an array.

Solution

Rust

Time O(n)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn min_operations(nums: Vec<i32>) -> i32 {
    // Insight: applying one operation on the entire array sets every element
    // to AND(nums[0..n-1]), making all elements equal in a single step.
    // Therefore the answer is:
    //   0 – all elements are already equal
    //   1 – otherwise
    if nums.iter().all(|&x| x == nums[0]) { 0 } else { 1 }
  }
}