func_code_string: #include <bits/stdc++.h>   using namespace std;   int r, c, s, e;   vector<int> adj[1000 * 1000 + 10];   int d[1000 * 1000 + 10];   char grid[1000][1000];   char access(int n) {     int x = n % c;     int y = n / c;     return grid[y][x];   }   void bfs(int n) {     queue<int> frontier;     frontier.push(n);     d[n] = 0;     while (!frontier.empty()) {       int u = frontier.front();       frontier.pop();       for (int i = 0; i < adj[u].size(); i++) {         int v = adj[u][i];         if (d[v] == -1) {           d[v] = d[u] + 1;           frontier.push(v);         }       }     }   }   int main() {     cin >> r >> c;     for (int i = 0; i < r; i++) {       for (int j = 0; j < c; j++) {         cin >> grid[i][j];       }     }     for (int i = 0; i < r; i++) {       for (int j = 0; j < c; j++) {         int cell = i * c + j;         if (grid[i][j] ==  T ) continue;         if (grid[i][j] ==  S )           s = cell;         else if (grid[i][j] ==  E )           e = cell;         if (grid[i - 1][j] !=  T  && i > 0) {           adj[cell].push_back(cell - c);           adj[cell - c].push_back(cell);         }         if (grid[i + 1][j] !=  T  && i < r - 1) {           adj[cell].push_back(cell + c);           adj[cell + c].push_back(cell);         }         if (grid[i][j - 1] !=  T  && j > 0) {           adj[cell].push_back(cell - 1);           adj[cell - 1].push_back(cell);         }         if (grid[i][j + 1] !=  T  && j < c - 1) {           adj[cell].push_back(cell + 1);           adj[cell + 1].push_back(cell);         }       }     }     memset(d, -1, sizeof(d));     bfs(e);     int shortest_path = d[s];     int ans = 0;     for (int i = 0; i < r * c; i++) {       char in = access(i);       if (in ==  T  || in ==  E  || in ==  S ) continue;       if (d[i] <= shortest_path && d[i] != -1) {         ans += in -  0 ;       }     }     cout << ans << endl;     return 0;   }   