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350. 两个数组的交集 II

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350. 两个数组的交集 II

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class Solution {
public:
    vector<int> intersect(vector<int>& nums1, vector<int>& nums2) {
        if(nums1.size() > nums2.size())
            return intersect(nums2, nums1);
        unordered_map<int, int> map;
        for(auto& num : nums1)
            ++map[num];
        vector<int> ret;
        for(auto& num : nums2)
        {
            if(map[num] > 0)
            {
                --map[num];
                ret.push_back(num);
            }
        }
        return ret;
    }
};
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class Solution {
public:
    vector<int> intersect(vector<int>& nums1, vector<int>& nums2) {
        sort(nums1.begin(), nums1.end());
        sort(nums2.begin(), nums2.end());
        int pt1 = 0, pt2 = 0;
        int length1 = nums1.size(), length2 = nums2.size();
        vector<int> ret;
        while(pt1 < length1 && pt2 < length2)
        {
            if(nums1[pt1] == nums2[pt2])
            {
                ret.push_back(nums2[pt2]);
                ++pt1;
                ++pt2;
            }else if(nums1[pt1] < nums2[pt2])
                ++pt1;
            else
                ++pt2;
        }
        return ret;
    }
};