1551-minimum-operations-to-make-array-equal.js

/**
 * 1551. Minimum Operations to Make Array Equal
 * https://leetcode.com/problems/minimum-operations-to-make-array-equal/
 * Difficulty: Medium
 *
 * You have an array arr of length n where arr[i] = (2 * i) + 1 for all valid values
 * of i (i.e., 0 <= i < n).
 *
 * 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] (i.e., perform arr[x] -=1 and arr[y] += 1). The goal
 * is to make all the elements of the array equal. It is guaranteed that all the elements
 * of the array can be made equal using some operations.
 *
 * Given an integer n, the length of the array, return the minimum number of operations
 * needed to make all the elements of arr equal.
 */

/**
 * @param {number} n
 * @return {number}
 */
var minOperations = function(n) {
  return n * n / 4;
};