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.

Input:n = 3Output:2Explanation:arr = [1, 3, 5] First operation choose x = 2 and y = 0, this leads arr to be [2, 3, 4] In the second operation choose x = 2 and y = 0 again, thus arr = [3, 3, 3].

Input:n = 6Output:9

- 1 <= n <= 10^4

Solution:

class Solution { public int minOperations(int n) { // 1 3 5 7 9 11 (6) // 1 3 5 7 9 (5) int min = 0; for (int i = 0; i < n / 2; i ++) { min += n - (2 * i + 1); } return min; } }