Two Pointers-349. Intersection of Two Arrays

Given two arrays, write a function to compute their intersection.

Example:
Given nums1 = [1, 2, 2, 1], nums2 = [2, 2], return [2].

Note:

• Each element in the result must be unique.
• The result can be in any order.

  • class Solution {  
    public:  
        vector<int> intersection(vector<int>& nums1, vector<int>& nums2) {  
            unordered_map<int, bool> hash;  
            vector<int> result;  
            for(auto val: nums1) hash[val] = true;  
            for(auto val: nums2)   
                if(hash.count(val))  
                {  
                    result.push_back(val);  
                    hash.erase(val);  
                }  
            return result;  
        }  
    };