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  1. #include <iostream>
  2. #include <stack>
  3.  
  4. using Point = std::pair<int, int>;
  5.  
  6. const int W = 5;
  7. const int H = 5;
  8.  
  9. bool m[W][H] = {{0, 0, 0, 1, 0},
  10. 				{0, 0, 0, 1, 0},
  11. 				{0, 0, 0, 1, 0},
  12. 				{0, 0, 0, 1, 0},
  13. 				{0, 0, 0, 1, 0}};
  14.  
  15. void fillUsingStack(bool m[W][H], int startX, int startY)
  16. {
  17. 	std::stack<Point> S;
  18. 	S.push({startX, startY});
  19.  
  20. 	while (!S.empty())
  21. 	{
  22. 		// get top element
  23. 		Point p = S.top();
  24. 		S.pop();
  25.  
  26. 		// check boundaries
  27. 		if (p.first < 0 || p.first >= W || p.second < 0 || p.second >= H)
  28. 			continue;
  29.  
  30. 		// skip when already colored
  31. 		if (m[p.first][p.second])
  32. 			continue;
  33.  
  34. 		// color current tile
  35. 		m[p.first][p.second] = 1;
  36.  
  37. 		// put all the neighbours on the stack
  38. 		S.push({p.first + 1, p.second});
  39. 		S.push({p.first - 1, p.second});
  40. 		S.push({p.first, p.second + 1});
  41. 		S.push({p.first, p.second - 1});
  42. 	}
  43. }
  44.  
  45. void printMap(bool m[W][H])
  46. {
  47. 	for (int y = 0; y < H; ++y)
  48. 	{
  49. 		for (int x = 0; x < W; ++x)
  50. 			std::cout << m[x][y] ? "1 " : "0 ";
  51. 		std::cout << "\n";
  52. 	}
  53. 	std::cout << std::endl;
  54. }
  55.  
  56. int main() {
  57. 	printMap(m);
  58.  
  59. 	fillUsingStack(m, 2, 2);
  60.  
  61. 	printMap(m);
  62. 	return 0;
  63. }
Success #stdin #stdout 0s 4264KB
comments (?)
stdin 
Standard input is empty
stdout 
00000
00000
00000
11111
00000

11111
11111
11111
11111
00000
https://ideone.com/YnjQn9
language:
C++14 (gcc 8.3)
created:
5 years ago
visibility:
public

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