LeetCode 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.

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题目要求：给两个数组，求他们的合集

 

class Solution {
public:
    vector<int> intersection(vector<int>& nums1, vector<int>& nums2) {
        map<int, int> map;
        vector<int> ret;
        for (auto &e : nums1)
            map[e] = 1;
        for (auto &e : nums2)
        {
            if (map.find(e)!=map.end()&&map[e]==1)
            {
                ret.push_back(e);
                ++map[e];
            }
        }
        return ret;
    }
};