• Source 
    1. #include <iostream>
    2. using namespace std;
    3.  
    4. int n, m;
    5. int seawater[102][102];
    6. int Hmax=0;
    7. void read ()
    8. {
    9. 	for (int i=1; i<=n; i++)
    10. 	{
    11. 		for (int j=1; j<=m; j++)
    12. 		{
    13. 			cin>>seawater[i][j];
    14. 			if (seawater[i][j]>Hmax) Hmax=seawater[i][j];
    15. 		}
    16. 	}
    17. }
    18.  
    19. int check[102][102];
    20. int check_connect[102][102];
    21. void init ()
    22. {
    23. 	for (int i=1; i<=n; i++)
    24. 	{
    25. 		for (int j=1; j<=m; j++)
    26. 		{
    27. 			check[i][j]=0;
    28. 			check_connect[i][j]=0;
    29. 		}
    30. 	}
    31. }
    32.  
    33. int extra;
    34. int x_ar[]={+1, +0, -1, +0};
    35. int y_ar[]={+0, -1, +0, +1};
    36. void loang (int i, int j)
    37. {
    38. 	check[i][j]=1;
    39. 	for (int k=0; k<4; k++)
    40. 	{
    41. 		int X=j+x_ar[k];
    42. 		int Y=i+y_ar[k];
    43. 		if (X>=1 && X<=m && Y>=1 && Y<=n)
    44. 		{
    45. 			if (check[Y][X]==0 && seawater[Y][X]<=extra) loang (Y, X);
    46. 		}
    47. 	}
    48. }
    49.  
    50. void DFS (int i, int j)
    51. {
    52. 	check_connect[i][j]=1;
    53. 	for (int k=0; k<4; k++)
    54. 	{
    55. 		int X=j+x_ar[k];
    56. 		int Y=i+y_ar[k];
    57. 		if (X>=1 && X<=m && Y>=1 && Y<=n)
    58. 		{
    59. 			if (check_connect[Y][X]==0 && check[Y][X]==check[i][j]) DFS (Y, X);
    60. 		}
    61. 	}
    62. }
    63.  
    64. int main ()
    65. {
    66. 	int t=0;
    67. 	while (1)
    68. 	{
    69. 		cin>>n>>m;
    70. 		if (n==0 && m==0) break;
    71. 		t++;
    72. 		read ();
    73. 		int kt=0;
    74. 		for (int k=0; k<=Hmax; k++)
    75. 		{
    76. 			extra=k;
    77. 			init ();
    78. 			for (int i=1; i<=n; i++)
    79. 			{
    80. 				for (int j=1; j<=m; j++)
    81. 				{
    82. 					if ((i==1 || i==n || j==1 || j==m) && seawater[i][j]<=k && check[i][j]==0) loang (i, j);
    83. 				}
    84. 			}
    85. 			//dem lien thong?
    86. 			int count_connect=0;
    87. 			for (int i=1; i<=n; i++)
    88. 			{
    89. 				for (int j=1; j<=m; j++)
    90. 				{
    91. 					if (check_connect[i][j]==0 && check[i][j]==0)
    92. 					{
    93. 						count_connect++;
    94. 						DFS (i, j);
    95. 					}
    96. 				}
    97. 			}
    98. 			if (count_connect>1)
    99. 			{
    100. 				kt=1;
    101. 				break;
    102. 			}
    103. 		}
    104. 		if (kt==1) cout<<"Case "<<t<<": Island splits when ocean rises "<<extra<<" feet."<<endl;
    105. 		else cout<<"Case "<<t<<": Island never splits."<<endl;
    106. 	}
    107. 	return 0;
    108. }