LeetCode No.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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题目链接：https://leetcode.com/problems/intersection-of-two-arrays/

题目大意：给定两个数组nums1和nums2，求nums1和nums2的交集。

思路：通过set来记录nums1中的数值，遍历nums2，nums2中元素nums2[i]在set中，则将其记录为答案，并从set中删除（去重）。

参考代码：

class Solution {public:    vector<int> intersection(vector<int>& nums1, vector<int>& nums2) {        set <int> sans ;        vector <int> ans ;        int n = nums1.size() , m = nums2.size() ;        for ( int i = 0 ; i < n ; i ++ )            sans.insert ( nums1[i] ) ;        for ( int i = 0 ; i < m ; i ++ )        {            if ( sans.find ( nums2[i] ) != sans.end() )            {                ans.push_back ( nums2[i] ) ;                sans.erase ( nums2[i] ) ;            }        }        sort ( ans.begin() , ans.end() ) ;        return ans ;    }};