Longest Common Subsequence(Solution Print)

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

const int maxN = 1001;
int grid[maxN][maxN];

int solve(char s[],char t[],int i,int j,int n,int m) {
    if (i > n or j > m) {
        return 0;
    }
    if (grid[i][j] != -1) {
        return grid[i][j];
    }
    if (s[i] == t[j]) {
        return grid[i][j] = 1 + solve(s,t,i + 1,j + 1,n,m);
    } else {
        return grid[i][j] = max(solve(s,t,i + 1,j,n,m),solve(s,t,i,j + 1,n,m));
    }
}

int main () {
     ios::sync_with_stdio(false);
     cin.tie(nullptr);
     cout.tie(nullptr);
     int T = 1;
     //~ cin >> T;
     for (int test_case = 1; test_case <= T; ++test_case) {
         int n,m;
         cin >> n >> m;
         char s[n + 1],t[m + 1];
         for (int i = 1; i <= n; ++i) {
             cin >> s[i];
         }
         for (int i = 1; i <= m; ++i) {
             cin >> t[i];
         }
         for (int i = 1; i <= n; ++i) {
             for (int j = 1; j <= m; ++j) {
                 grid[i][j] = -1;
             }
         }
         solve(s,t,1,1,n,m);
         for (int i = 1; i <= n; ++i) {
             for (int j = 1; j <= m; ++j) {
                 cout << grid[i][j] << " ";
             }
             cout << "\n";
         }
         char lcs[grid[1][1] + 1];
         int i = 1,j = 1;
         int idx = 1;
         while (i <= n and j <= m) {
             if (s[i] == t[j]) {
                 lcs[idx++] = s[i];
                 ++i,++j;
             } else if (grid[i + 1][j] > grid[i][j + 1]) {
                 ++i;
             } else{
                 ++j;
             }
         }
         for (i = 1; i <= grid[1][1]; ++i) {
             cout << lcs[i];
         }
     }
}