leetcode1877. Minimize Maximum Pair Sum in Array

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: 7Explanation: 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: 8Explanation: 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.

Constraints:

• n == nums.length

• 2 <= n <= 105

• n is even.

• 1 <= nums[i] <= 105

其实就是排序，最小的跟最大的配对，以此类推，然后这些配对中找最大的。

Runtime: 73 ms, faster than 42.32% of Java online submissions for Minimize Maximum Pair Sum in Array.

Memory Usage: 106.8 MB, less than 50.66% of Java online submissions for Minimize Maximum Pair Sum in Array.