561. Array Partition I

题目来源【Leetcode】

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].

这道题很简单，直接放代码

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