• Source 
    1. #include <iostream>
    2. #include <string>
    3. using namespace std;
    4.  
    5. int N;
    6. char banco[31][31];
    7. char tg[4];
    8.  
    9. int isOutside (int i, int j)
    10. {
    11. 	if (i<1 || N<i) return 1;
    12. 	if (j<1 || N<j) return 1;
    13. 	return 0;
    14. }
    15.  
    16. int kt (char dk)
    17. {
    18. 	for (int i=1; i<=3; i++)
    19. 	{
    20. 		if (tg[1]==tg[2] && tg[2]==tg[3] && tg[3]==dk) return 1;
    21. 	}
    22. 	return 0;
    23. }
    24.  
    25. int layngang (int i, int j, char dk)
    26. {
    27. 	int iNext = i;
    28. 	int jNext = j+2;
    29. 	if (isOutside (iNext, jNext)==1) return 0;
    30. 	else
    31. 	{
    32. 		tg[1]=banco[i][j];
    33. 		tg[2]=banco[i][j+1];
    34. 		tg[3]=banco[i][j+2];
    35. 		if (kt(dk)==1) return 1;
    36. 	}
    37. 	return 0;
    38. }
    39.  
    40. int laydoc (int i, int j, char dk)
    41. {
    42. 	int iNext = i+2;
    43. 	int jNext = j;
    44. 	if (isOutside (iNext, jNext)==1) return 0;
    45. 	else
    46. 	{
    47. 		tg[1]=banco[i][j];
    48. 		tg[2]=banco[i+1][j];
    49. 		tg[3]=banco[i+2][j];
    50. 		if (kt(dk)==1) return 1;
    51. 	}
    52. 	return 0;
    53. }
    54.  
    55. int laycheo1 (int i, int j, char dk)
    56. {
    57. 	int iNext = i+2;
    58. 	int jNext = j+2;
    59. 	if (isOutside (iNext, jNext)==1) return 0;
    60. 	else
    61. 	{
    62. 		tg[1]=banco[i][j];
    63. 		tg[2]=banco[i+1][j+1];
    64. 		tg[3]=banco[i+2][j+2];
    65. 		if (kt(dk)==1) return 1;
    66. 	}
    67. 	return 0;
    68. }
    69.  
    70. int laycheo2 (int i, int j, char dk)
    71. {
    72. 	int iNext = i+2;
    73. 	int jNext = j-2;
    74. 	if (isOutside (iNext, jNext)==1) return 0;
    75. 	else
    76. 	{
    77. 		tg[1]=banco[i][j];
    78. 		tg[2]=banco[i+1][j-1];
    79. 		tg[3]=banco[i+2][j-2];
    80. 		if (kt(dk)==1) return 1;
    81. 	}
    82. 	return 0;
    83. }
    84.  
    85. int main ()
    86. {
    87. 	//IN;
    88. 	cin>>N;
    89. 	string xau;
    90. 	for (int i=1; i<=N; i++)
    91. 	{
    92. 		cin>>xau;
    93. 		for (int j=1; j<=N; j++)
    94. 		{
    95. 			banco[i][j]=xau[j-1];
    96. 		}
    97. 	}
    98. 	for (int i=1; i<=N; i++)
    99. 	{
    100. 		for (int j=1; j<=N; j++)
    101. 		{
    102. 			if (banco[i][j]!='.')
    103. 			{
    104. 				char DK=banco[i][j];
    105. 				if (layngang (i, j, DK)!=0 || laydoc (i, j, DK)!=0 || laycheo1 (i, j, DK)!=0 || laycheo2 (i, j, DK)!=0)
    106. 				{
    107. 					cout<<DK;
    108. 					return 0;
    109. 				}
    110. 			}
    111. 		}
    112. 	}
    113. 	cout<<"ongoing";
    114. 	return 0;
    115. }