548. 两数组的交 II 排序+双指针

vector<int> intersection(vector<int> nums1, vector<int> nums2) {
        // write your code here
        if(nums1.empty()||nums2.empty())     //特殊情况
        return vector<int>();  
        sort(nums1.begin(),nums1.end());
        sort(nums2.begin(),nums2.end());
         //双指针
        auto beg1=nums1.begin();
        auto beg2=nums2.begin();  
        vector<int> res;
         //双指针遍历
        while(beg1!=nums1.end()&&beg2!=nums2.end())
        {
            if(*beg1==*beg2)
            {
                res.push_back(*beg1);
                beg1++;
                beg2++;
            }
            else if(*beg1<*beg2)
            {
                beg1++;
            }
            else beg2++;
        }
        return res;
    }