lec10_78.cpp

class Solution {
    public:
    
        int longestCommonSubsequence(string s, string t) {
            
            int n = s.size();
            int m = t.size();
    
            vector<vector<int>>dp( n+1 , vector<int>( m+1 ,-1));
    
            for(int j = 0 ; j<=m;j++) dp[0][j] = 0;
            for(int i = 0 ; i<=n;i++) dp[i][0] = 0 ;
            for(int i = 1 ;i<=n;i++){
    
                for(int j = 1 ;j<=m;j++){
                        if(s[i-1] == t[j-1]) dp[i][j]= 1 + dp[i-1 ][ j-1 ];
                        else
                          dp[i][j]=max(dp[i-1][j],dp[i ][ j-1]); 
                }
            }
            return dp[n][m]; 
        }
    };