> For the complete documentation index, see [llms.txt](https://dfine.gitbook.io/leetcode/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dfine.gitbook.io/leetcode/349.intersection_of_two_arrays.md).

# 349.Intersection of Two Arrays

**349.Intersection of Two Arrays**

难度:Easy

> 给定两个数组，编写一个函数来计算它们的交集。

```
示例 1:
输入: nums1 = [1,2,2,1], nums2 = [2,2]
输出: [2]
示例 2:
输入: nums1 = [4,9,5], nums2 = [9,4,9,8,4]
输出: [9,4]
说明:
输出结果中的每个元素一定是唯一的。
我们可以不考虑输出结果的顺序。
```

代码如下：

```
class Solution {
public:
    vector<int> intersection(vector<int>& nums1, vector<int>& nums2) {
        unordered_set<int>n1(nums1.begin(),nums1.end());
        unordered_set<int>n2(nums2.begin(),nums2.end());
        vector<int> res;
        for(auto each: n1)
        {
           // cout<< each<<endl;
            if(n2.count(each)) res.push_back(each);
        }
        return res;
    }
};
```

> 执行用时 :20 ms, 在所有 C++ 提交中击败了31.29%的用户\
> 内存消耗 :9.4 MB, 在所有 C++ 提交中击败了39.10%的用户


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