leetcode 561. Array Partition I 数组元素分组的最小值的和的最大值+直接排序即可-蒲公英云

leetcode 561. Array Partition I 数组元素分组的最小值的和的最大值+直接排序即可

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].

本题题意很简单，直接排序然后求和即可

代码如下：

#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <string>
#include <climits>
#include <algorithm>
#include <sstream>
#include <functional>
#include <bitset>
#include <numeric>
#include <cmath>
using namespace std;
class Solution 
{
public:
    int arrayPairSum(vector<int>& nums) 
    {
        sort(nums.begin(), nums.end());
        int sum = 0;
        for (int i = 0; i < nums.size(); i++)
        {
            if (i % 2 == 0)
                sum += nums[i];
        }
        return sum;
    }
};