Pair elements

Given an array of 2n integers, your task is to group these integers into n pairs of integer, say (a1, b1), (a2, b2), …, (an, bn) which makes sum of min(ai, bi) 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:

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

Github: code.dennyzhang.com

Credits To: leetcode.com

Leave me comments, if you have better ways to solve.

## https://code.dennyzhang.com/array-partition-i class Solution(object): def arrayPairSum(self, nums): """ :type nums: List[int] :rtype: int """ ret = 0 sorted_nums = sorted(nums) i = 0 while i < len(sorted_nums)/2: ret = ret + sorted_nums[i*2] i = i + 1 return ret