561. Array Partition I

array

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).

  • code
class Solution:
    def arrayPairSum(self, nums: List[int]) -> int:
        nums.sort()
        res = 0
        for i in range(0,len(nums),2):
            res += nums[i]
        return res
  • code
class Solution:
    def arrayPairSum(self, nums: List[int]) -> int:
        return sum(sorted(nums)[::2])