349. 两个数组的交集

 

class Solution {
public:
    vector<int> intersection(vector<int>& nums1, vector<int>& nums2) {
        unordered_set<int> ans_set;
        unordered_set<int> num1_set(nums1.begin(), nums1.end());
        for(int elem : nums2){
            if(num1_set.find(elem) != num1_set.end()){
                ans_set.insert(elem);
            }
        }
        return vector<int>(ans_set.begin(), ans_set.end());
    }
};