LeetCode : Intersection of Two Arrays II

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

Example:
Given nums1 = [1, 2, 2, 1], nums2 = [2, 2], return [2, 2].

Note:
Each element in the result should appear as many times as it shows in both arrays.
The result can be in any order.

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