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  1. #include <iostream>
  2. #include <vector>
  3. #include <set>
  4. #include <string>
  5. using namespace std;
  6.  
  7. int n, m;
  8. vector<vector<bool>> la;
  9. set<pair<int, int>> wall;
  10.  
  11. bool valid(int i, int j) {
  12.     return i >= 0 && i < n && j >= 0 && j < m && !la[i][j] && wall.find({i, j}) == wall.end();
  13. }
  14.  
  15. void dfs(int i, int j) {
  16.     if (!valid(i, j)) return;
  17.     la[i][j] = true;
  18.     dfs(i + 1, j);
  19.     dfs(i - 1, j);
  20.     dfs(i, j + 1);
  21.     dfs(i, j - 1);
  22. }
  23.  
  24. int main() {
  25.     cin >> n >> m;
  26.  
  27.     la.resize(n, vector<bool>(m, false));
  28.     vector<vector<int>> a(n, vector<int>(m, 0));
  29.  
  30.     string ch;
  31.     for (int i = 0; i < n; i++) {
  32.         cin >> ch;
  33.         for (int j = 0; j < m; j++) {
  34.             if (ch[j] == '#') {
  35.                 a[i][j] = 1;
  36.                 wall.insert({i, j});
  37.             } else {
  38.                 a[i][j] = 0;
  39.             }
  40.         }
  41.     }
  42.  
  43.     int nb = 0;
  44.     for (int i = 0; i < n; i++) {
  45.         for (int j = 0; j < m; j++) {
  46.             if (!la[i][j] && wall.find({i, j}) == wall.end()) {
  47.                 dfs(i, j);
  48.                 nb++;
  49.             }
  50.         }
  51.     }
  52.  
  53.     cout << nb << endl;
  54.     return 0;
  55. }
  56.  
Success #stdin #stdout 0.01s 5280KB
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https://ideone.com/TKFhLm
language:
C++ (gcc 8.3)
created:
1 day ago
visibility:
public

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