LeetCode561

本题注意点：list的骚操作

    1、sum(list)求和；

    2、list[::step] 得到子列表

import numpy as np

def arrayPairSum(nums):
    """
    :type nums: List[int]
    :rtype: int
    """
    nums.sort()
    return sum(nums[::2])

    # version2：
    # sum = 0
    # for i in range(0, len(nums), 2):
    #     sum += nums[i]
    # return sum

# sample:
nums = [1,4,3,2]
print(arrayPairSum(nums))