easy soln cpp 1ms soln 
IntuitionApproachUse a Hash Map (mp) to store frequencies of elements across all rows.Traverse each row and insert its elements into mp.
Since each row contains
# Intuition
<!-- Describe your first thoughts on how to solve this problem. -->

# Approach
<!-- Describe your approach to solving the problem. -->
Use a Hash Map (mp) to store frequencies of elements across all rows.

Traverse each row and insert its elements into mp.
Since each row contains unique elements, adding an element from a row only once ensures correctness.
Traverse the map (mp) to find common elements.

If an element appears in all rows, its frequency will be equal to the total number of rows (n).
Add such elements to the answer list.

# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->

- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->

# Code
```cpp []
class Solution {
public:
    vector<int> intersection(vector<vector<int>>& nums) {
        map<int,int>mp;
        vector<int>v;
      for(int i=0;i<nums.size();i++){
        for(int j=0;j<nums[i].size();j++){
            mp[nums[i][j]]++;
        }
      }
        int n=nums.size();
        for(auto i=mp.begin();i!=mp.end();i++){
            if(i->second==n){
                v.push_back(i->first);
            }
        
      }
      sort(v.begin(),v.end());
      return v;  
    }
};
```
['C++']