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  1. #include <iostream>
  2. #include <queue>
  3. using namespace std;
  4. int a[1000][1000];
  5. int d[1000][1000];
  6. int dx[] = { 0,0,1,-1 };
  7. int dy[] = { 1,-1,0,0 };
  8. int main() {
  9. 	int m, n;
  10. 	cin >> m >> n;
  11. 	queue<pair<int, int>> q;
  12. 	for (int i = 0; i < n; i++) {
  13. 		for (int j = 0; j < m; j++) {
  14. 			cin >> a[i][j];
  15. 			d[i][j] = -1;
  16. 			if (a[i][j] == 1) {
  17. 				q.push(make_pair(i, j));
  18. 				d[i][j] = 0; //이미 익어있는 것이므로 날짜증가X
  19. 			}
  20. 		}
  21. 	}
  22. 	while (!q.empty()) {
  23. 		int x = q.front().first;
  24. 		int y = q.front().second;
  25. 		q.pop();
  26. 		for (int k = 0; k < 4; k++) {
  27. 			int nx = x + dx[k];
  28. 			int ny = y + dy[k];
  29. 			if (nx >= 0 && nx < n&&ny >= 0 && ny < m) {
  30. 				if (a[nx][ny] == 0 && d[nx][ny] == -1) {
  31. 					d[nx][ny] = d[x][y] + 1;
  32. 					q.push(make_pair(nx, ny));
  33. 				}
  34. 			}
  35. 		}
  36. 	}
  37. 	int ans = 0;
  38. 	for (int i = 0; i < n; i++) {
  39. 		for (int j = 0; j < m; j++) {
  40. 			if (ans < d[i][j])
  41. 				ans = d[i][j];
  42. 			else if (a[i][j] == 0 && d[i][j] == -1)
  43. 				ans = -1;
  44. 		}
  45. 	}
  46.  
  47. 	cout << ans << '\n';
  48. 	return 0;
  49. }
Success #stdin #stdout 0s 4576KB
comments (?)
stdin
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3 3

0 -1 -1

-1 -1 0

0 -1 1
stdout
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0
https://ideone.com/RyhIvJ
language:
C++14 (gcc 8.3)
created:
6 years ago
visibility:
public

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