91. Intersection of Two Arrays

-350. Intersection of Two Arrays II My Submissions QuestionEditorial Solution
Total Accepted: 5040 Total Submissions: 12104 Difficulty: Easy
Given two arrays, write a function to compute their intersection.

Example:
Given nums1 = [1, 2, 2, 1], nums2 = [2, 2], return [2, 2].
数组求交集，元素不唯一

和上一题不同，这一题，统计相同元素的个数
push的时候做参考

class Solution {public:    vector<int> intersect(vector<int>& nums1, vector<int>& nums2) {        int n1=nums1.size(),n2=nums2.size();        unordered_map<int,int> minset; //较小容器集合，结果集合        vector<int> res;  //保存结果        auto it_beg = n1<n2?nums1.begin():nums2.begin();         auto it_end = n1<n2?nums1.end():nums2.end();          while(it_beg!=it_end){                     //将较小容器元素集合保存,并统计个数            if(minset.count(*it_beg))minset[*it_beg]++;            else minset[*it_beg]=1;            ++it_beg;        }        it_beg = n1>=n2?nums1.begin():nums2.begin();        it_end = n1>=n2?nums1.end():nums2.end();        while(it_beg!=it_end){             //扫描较大容器集合，如果是二者交集存入结果集            if(minset.count(*it_beg)){                if(minset[*it_beg]>0)res.push_back(*it_beg); //push的个数足够了就不再push                --minset[*it_beg];            };            ++it_beg;        }        return res;    }};