Array Partition I

Description

Given an array of 2n integers, your task is to group these integers into n pairs of integer, say (a₁, b₁), (a₂, b₂), ..., (a_n, b_n) which makes sum of min(a_i, b_i) for all i from 1 to n as large as possible.

Example 1:

Input: [1,4,3,2]
Output: 4
Explanation: n is 2, and the maximum sum of pairs is 4 = min(1, 2) + min(3, 4).

Note:

1. n is a positive integer, which is in the range of [1, 10000].
2. All the integers in the array will be in the range of [-10000, 10000].

Solution(javascript)

/**
 * @param {number[]} nums
 * @return {number}
 */
const arrayPairSum = function (nums) {
  nums.sort((a, b) => a - b)
  let sum = 0
  for (let i = 0; i < nums.length; i += 2) {
    sum += Math.min(nums[i], nums[i + 1])
  }
  return sum
}