Minimum operations to make array equal

Math

82.7% acceptance

Feb 25, 2026

1502

187

You have an array arr of length n where arr[i] = (2 * i) + 1 for all valid values of i. In one operation, you can select two indices x and y where 0 <= x, y < n and subtract 1 from arr[x] and add 1 to arr[y]. The goal is to make all the elements of the array equal. Given an integer n, return the minimum number of operations needed to make all the elements of arr equal.

Solution

Rust

Time O(1)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn min_operations(n: i32) -> i32 {
    // arr[i] = 2i+1, target = n, ans = n*n/4
    n * n / 4
  }
}