LeetCode: Array Partition I Solution

Approach

Greedily make pairs of smallest and next smallest numbers

Sort array for easy iteration

Why? Let's take this sorted array

11 2 3 4

If we pair

with , will miss as min in a pair

Implementation

1var arrayPairSum = function (nums) {
2  return nums
3    .sort((a, b) => (a < b ? -1 : 1))
4    .filter((_, index) => index % 2 === 0)
5    .reduce((sum, num) => sum + num, 0)
6}