[LeetCode]349. Intersection of Two Arrays

[LeetCode]349. Intersection of Two Arrays

题目描述

思路

使用map存数组1
遍历数组2的元素
如果map中有记录，放入结果中，并将map中的记录擦除

代码

#include <iostream>
#include <vector>
#include <unordered_map>
using namespace std;

class Solution {
public:
    vector<int> intersection(vector<int>& nums1, vector<int>& nums2) {
        vector<int> res;
        unordered_map<int, int> n1;
        for (int p : nums1)
            ++n1[p];
        for (int p : nums2)
            if (n1.count(p)) {
                res.push_back(p);
                n1.erase(p);
            }

        return res;
    }
};

int main() {
    vector<int> res, nums1 = { 1, 2, 2, 1 }, nums2 = { 2, 2, 1 };
    Solution s;
    res = s.intersection(nums1, nums2);

    for (int p : res) {
        cout << p << " ";
    }
    cout << endl;

    system("pause");
}