Minimize_Maximum_Pair_Sum_In_Array.js

/*
Minimize Maximum Pair Sum in Array
https://leetcode.com/problems/minimize-maximum-pair-sum-in-array/description/

The pair sum of a pair (a,b) is equal to a + b. The maximum pair sum is the largest pair sum in a list of pairs.

For example, if we have pairs (1,5), (2,3), and (4,4), the maximum pair sum would be max(1+5, 2+3, 4+4) = max(6, 5, 8) = 8.
Given an array nums of even length n, pair up the elements of nums into n / 2 pairs such that:

Each element of nums is in exactly one pair, and
The maximum pair sum is minimized.
Return the minimized maximum pair sum after optimally pairing up the elements.



Example 1:

Input: nums = [3,5,2,3]
Output: 7
Explanation: The elements can be paired up into pairs (3,3) and (5,2).
The maximum pair sum is max(3+3, 5+2) = max(6, 7) = 7.


Example 2:

Input: nums = [3,5,4,2,4,6]
Output: 8
Explanation: The elements can be paired up into pairs (3,5), (4,4), and (6,2).
The maximum pair sum is max(3+5, 4+4, 6+2) = max(8, 8, 8) = 8.
*/

/**
 * @param {number[]} nums
 * @return {number}
 */
var minPairSum = function(nums) {
  nums.sort((a, b) => a-b);
  let i = 0, j = nums.length - 1;
  let max = -Infinity;
  while (i < j) {
    max = Math.max(max, nums[i++] + nums[j--]);
  }
  return max;
};

module.exports.minPairSum = minPairSum;