func_code_string: #include <bits/stdc++.h>   using namespace std;   int memo[77][107][107];   inline int index(char ch) { return (ch ==  @ ) ? 0 : ch -  a ; }   bool eval(char ch, int i, int j, vector<vector<pair<int, char>>> &adj) {     int val = memo[index(ch)][i][j];     if (val == 1) return true;     if (val == 2) return false;     for (auto nxt : adj[i]) {       if (ch <= nxt.second) {         if (!eval(nxt.second, j, nxt.first, adj)) {           memo[index(ch)][i][j] = 1;           return true;         }       }     }     memo[index(ch)][i][j] = 2;     return false;   }   int main() {     cin.tie(0);     cout.tie(0);     ios_base::sync_with_stdio(0);     int n, m;     cin >> n >> m;     vector<vector<pair<int, char>>> adj(n + 1);     for (int i = 0; i < m; i++) {       int u, v;       char c;       cin >> u >> v >> c;       adj[u].push_back({v, c});     }     for (int i = 1; i <= n; i++) {       for (int j = 1; j <= n; j++) cout << (eval( @ , i, j, adj) ?  A  :  B );       cout <<   n ;     }     return 0;   }   