func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 102, M = 102 * 102;   int n, m;   vector<pair<int, int> > g[N];   char ans[N][N];   char dp[N][N][28] = {0};   void input() {     cin >> n >> m;     for (int i = (0); i < (m); ++i) {       int u, v;       char ch;       cin >> u >> v >> ch;       u--, v--;       g[u].push_back(make_pair(v, ch -  a ));     }   }   int dfs(int u, int v, char c) {     if (dp[u][v][c] != 0) return dp[u][v][c];     for (auto x : g[u]) {       int h = x.first;       char k = x.second;       int win = 0;       if (k >= c) {         win = dfs(v, h, k);         if (win == 2) {           dp[u][v][c] = 1;           return 1;         }       }     }     dp[u][v][c] = 2;     return 2;   }   void solve() {     for (int i = (0); i < (n); ++i) {       for (int j = (0); j < (n); ++j) {         ans[i][j] = ((dfs(i, j, 0) == 1) ?  A  :  B );       }     }   }   void output() {     for (int i = (0); i < (n); ++i) {       for (int j = (0); j < (n); ++j) {         cout << ans[i][j];       }       cout <<   n ;     }   }   int main() {     input();     solve();     output();   }   