Leetcode 561. Array Splitting I (Simple Greedy Thought)

Simple greedy thinking, after sorting, you can pair them in pairs.

class Solution {
public:
    int arrayPairSum(vector<int>& nums) {
        sort(nums.begin(),nums.end());
        int res = 0;
        for(int i=0;i<nums.size();i+=2){
            res += nums[i];
        }
        return res;
    }
};