[LeetCode] #561. Array Partition I

題目

Given an integer array nums of 2n integers, group these integers into n pairs (a1, b1), (a2, b2), ..., (an, bn) such that the sum of min(ai, bi) for all i is maximized. Return the maximized sum.

直覺解

構想：

由小到大排序之後，兩兩一組取最小的數字相加，也就是，取 index 為偶數的數字相加。

python3 實作：

class Solution:
    def arrayPairSum(self, nums: List[int]) -> int: 

        nums.sort() 

        return sum(nums[::2])

效能：

Runtime: 264 ms, faster than 62.64% of python3 online submissions for Array Partition I.
Memory Usage: 16.7 MB, less than 82.74% of python3 online submissions for Array Partition I.