# 1748.sum-of-unique-elements

## Statement

• Difficulty: Easy
• Tag: `数组` `哈希表` `计数`

``````输入：nums = [1,2,3,2]

``````

``````输入：nums = [1,1,1,1,1]

``````

``````输入：nums = [1,2,3,4,5]

``````

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

• Link: Sum of Unique Elements
• Difficulty: Easy
• Tag: `Array` `Hash Table` `Counting`

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.
``````

Constraints:

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

## Solution

``````from typing import Counter, List

class Solution:
def sumOfUnique(self, nums: List[int]) -> int:
m = Counter(nums)
return sum(filter(lambda x: m[x] == 1, m.keys()))
``````