昨日当年

题目乍一看很复杂的样子，其实就是把数组按增序排序然后把每相邻两个元素之间最小的那个加起来就行了

js：

/**
 * @param {number[]} nums
 * @return {number}
 */
var arrayPairSum = function(nums) {
    nums.sort(function(a,b){return a-b;})
    let answer = 0
    for (let i = 0; i<nums.length;){
        answer = answer + nums[i]
        i = i+2
    }
    return answer
};

java:

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