leetcode 1748. Sum of Unique Elements（python）

描述

You are given an integer array nums. The unique elements of an array are the elements that appear exactly once in the array.

Return the sum of all the unique elements of nums.

Example 1:

Input: nums = [1,2,3,2]
Output: 4
Explanation: The unique elements are [1,3], and the sum is 4.

Example 2:

Input: nums = [1,1,1,1,1]
Output: 0
Explanation: There are no unique elements, and the sum is 0.

Example 3:

Input: nums = [1,2,3,4,5]
Output: 15
Explanation: The unique elements are [1,2,3,4,5], and the sum is 15.

Note:

1 <= nums.length <= 100
1 <= nums[i] <= 100

解析

根据题意，只需要使用字典对 nums 进行统计，将出现个数为 1 的值求和即可。

解答

class Solution(object):
    def sumOfUnique(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        result = 0
        c = collections.Counter(nums)
        for k,v in c.items():
            if v==1:
                result += k
        return result

运行结果

Runtime: 16 ms, faster than 96.21% of Python online submissions for Sum of Unique Elements.
Memory Usage: 13.5 MB, less than 44.23% of Python online submissions for Sum of Unique Elements.

原题链接：https://leetcode.com/problems/sum-of-unique-elements/