561. Array Partition I

Leetcode 链接

题目

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].

题意解析

给出一个数组，总数为 2n 个。要求两两分为一组。分组后每一组的较小值的总和为最大。

解决方案

• 两两配对后，要求的是每一组的较小值的和最大，那么就要保证每一组的较大值要尽量小

Go 代码

func arrayPairSum(nums []int) int {
    sort.Slice(nums, func(i, j int) bool {
        return nums[i] < nums[j]
    })

    res := 0

    for i:=0; i+1<len(nums); i = i+2{
        res += nums[i]
    }

    return res
}