In this post, we are going to discuss leetcode 1748 — Sum of Unique Elements, which is recently asked in Meta interviews.
Problem Analysis
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.This is a standard hash map problem. We can simply use a hash map to count the occurrence of each integer, then loop on the hash map to sum up the unique ones.
Code Implementation
Base on the analysis above, below is my implementation of the problem.
