20 Longest common subsequence Memoization

--> Longest Common Subsequence Continued...
Memoization Approach -

Video Link  : https://youtu.be/g_hIx4yn9zg

#include<bits/stdc++.h>
using namespace std;

    
  
    int LCS(string s1,string s2,int n,int m, vector<vector<int>> &t)
    {
        
        
        if(n==0 || m==0)
        {
            return 0;
        }
        
        if(t[n][m]!=-1)
        {
            return t[n][m];
        }
        
        if(s1[n-1]==s2[m-1])
        {
            return t[n][m]= 1+LCS(s1,s2,n-1,m-1,t);
        }
        
        else{
            return t[n][m]= max(LCS(s1,s2,n-1,m,t), LCS(s1,s2,n,m-1,t));
        }
        
        
    }
        
     
int main()
{
   
 
    
        int n, m; cin >> n >> m;
        string s1, s2;
        cin >> s1 >> s2;
        
  vector<vector<int>> t (n+1,vector<int> (m+1,-1));
        
      int ans =  LCS(s1,s2,n,m,t);
      cout<<ans;

     return 0; 
}