# LeetCode 1877. Minimize Maximum Pair Sum in Array

## Intuition

- Pairing the biggest number with the smallest number leads to the minimum pair sum for the biggest number.
- Remove them from the array, find the next biggest and smallest number, and pair them.
- Find the maximum pair sum while pairing and return it after the array is empty.

## Approach

- Sort
`nums`

in ascending order. - Initialise
`ans`

with 0, which represents that the maximum pair sum in`nums`

is 0. - Iterate over
`nums`

from 0 to`nums.size() / 2 - 1`

. - On each iteration:
- Pair
`nums[i]`

with`nums[nums.size()-1-i]`

. - Calculate their pair sum and update
`ans`

.

- Pair
- Return
`ans`

.

Pseudocode of this problem:

1 | minPairSum(nums): |

## Complexity

Time complexity: $O(nlogn)$.

Sorting

`nums`

in ascending order is $O(nlogn)$.$n / 2$ iterations to pair elements and find the maximum pair sum.

In each iteration:

- Calculate the pair sum and update the maximum pair sum is $O(1)$.

Overall complexity is $O(nlogn)$.

Space complexity: $O(1)$.

## Code

1 | class Solution { |