1877. 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.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
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.

Constraints:

n == nums.length
2 <= n <= 105
n is even.
1 <= nums[i] <= 105

Solution

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
class Solution {
    public int minPairSum(int[] nums) {
        Arrays.sort(nums);
        int max = 0;
        int n = nums.length ;
        for (int i = 0 ; i < n/ 2; i++) {
            max = Math.max(nums[i] + nums[n - i - 1], max);
        }
        return max;
    }
}

Solution#

Solution