[] LeetCode the intersection of two arrays II

Given two arrays, write a function to compute their intersection.

Example 1:

Input: nums1 = [1,2,2,1], nums2 = [2,2]
 Output: [2,2]

Example 2:

Input: nums1 = [4,9,5], nums2 = [9,4,9,8,4]
 Output: [4,9]

Description:

• The output frequency of each element appears, should be consistent with the number of elements that appear in both arrays.
• We can not consider the order of output.

Advanced:

• If given array is already sorted it? How will you optimize your algorithm?
• If  nums1  size than  nums2  much smaller, which method is better?
• If  nums2  elements stored on disk, the disk memory is limited and you can not be loaded once all the elements into memory, how can you do?

class Solution {
public:
    vector<int> intersect(vector<int>& nums1, vector<int>& nums2) {
        sort(nums1.begin(),nums1.end());
        sort(nums2.begin(),nums2.end());
        int p=0;
        int q=0;
        vector<int> t;
        for(;p<nums1.size()&&q<nums2.size();){
            if(nums1[p]==nums2[q]){
                t.push_back(nums1[p]);
                p++;
                q++;
            }else if(nums1[p]>nums2[q]){
                q++;
            }else if(nums1[p]<nums2[q]){
                p++;
            }
        }return t;
    }
};