LeetCode: Minimum Operations To Make Array Equal Solution

1/**
2 * @param {number} n
3 * @return {number}
4 */
5// O(n^2)
6var minOperations = function (n) {
7  const med = 2 * Math.floor(n / 2) + (n % 2 === 0 ? 0 : 1)
8  return (
9    Array.from({ length: n }, (_, i) => 2 * i + 1)
10      .map(el => Math.abs(med - el))
11      .reduce((acc, el) => acc + el, 0) / 2
12  )
13}
14
15// O(1)
16var minOperations = function (n) {
17  return Math.floor(n / 2) * Math.ceil(n / 2)
18}