func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 503;   int m, n, vis[N][N];   vector<int> adj[N * N];   void init() {     ios::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);   }   int id(int x, int y) { return (x - 1) * n + y; }   struct ds {     char c;     int x, y;   };   vector<ds> V;   void print(int u, int cc, int type = -1) {     int x = (u - 1) / n + 1, y = u - (x - 1) * n;     if (adj[u].size() == 0 && !type) {       V.push_back((ds){ R , x, y});       return;     }     V.push_back((ds){ B , x, y});     for (int v : adj[u]) print(v, cc, 0);     if (!type) V.push_back((ds){ D , x, y}), V.push_back((ds){ R , x, y});   }   int cc = 0;   queue<pair<int, int> > Q;   int hang[4] = {0, 0, 1, -1};   int cot[4] = {1, -1, 0, 0};   void build(int orgx, int orgy, int cc) {     vis[orgx][orgy] = cc;     Q.push({orgx, orgy});     while (Q.size()) {       int x = Q.front().first, y = Q.front().second;       Q.pop();       for (int t = 0; t <= (int)3; ++t) {         int nx = x + hang[t], ny = y + cot[t];         if (nx < 1 || nx > m || ny < 1 || ny > n || vis[nx][ny]) continue;         adj[id(x, y)].push_back(id(nx, ny));         vis[nx][ny] = cc;         Q.push({nx, ny});       }     }     print(id(orgx, orgy), cc);   }   void solve() {     cin >> m >> n;     for (int i = 1; i <= (int)m; ++i)       for (int j = 1; j <= (int)n; ++j) {         char c;         cin >> c;         if (c ==  # ) vis[i][j] = -1;       }     for (int i = 1; i <= (int)m; ++i)       for (int j = 1; j <= (int)n; ++j)         if (!vis[i][j]) build(i, j, ++cc);     cout << V.size() <<   n ;     for (ds it : V) cout << it.c <<     << it.x <<     << it.y <<   n ;   }   int main() {     init();     solve();   }   