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].

超级没意思的一道题目

public class Solution {
    public int arrayPairSum(int[] nums) {
        Arrays.sort(nums);
        int res = 0;
        int i=0;
        while(i<nums.length){
            res +=nums[i];
            i =i+2;
        }
        return res;
    }
}