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:

1. n is a positive integer, which is in the range of [1, 10000].
2. All the integers in the array will be in the range of [-10000, 10000].

思路

• 每一个元组里面的相差要最小，就能使得相加之后和最小

• 先排序，然后两两进行组合
• 1， 3， 5， 。。。。直接进行相加

python实践

#!/usr/bin/env python
# _*_ coding:utf-8 _*_

class Solution:
    def arrayPairSum(self, nums):
        nums = sorted(nums)
        total = 0
        i = 0
        while i < len(nums):
            total += nums[i]
            i += 2
        print(total)
        return total


if __name__ == '__main__':
    num = [1,4,3,2]
    Solution().arrayPairSum(num)

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