USACO 2.1 The Castle

#include <stdio.h>
#define DEBUG 1
#define TESTCASES 8

int numOfRows, numOfColumns;
int wall[50][50][4];
int numOfRooms;
int roomNumArray[50][50];
int roomSize[2501];
int directionArray[4][2] = {{0, -1}, {-1, 0}, {0, 1}, {1, 0}};

void printRoomNumArray(){
int i, j;
for (i = 0; i < numOfRows; i++){
for (j = 0; j < numOfColumns; j++)
printf("%d ", roomNumArray[i][j]);
printf("\n");
}
printf("\n");
}

void numberRoom(int row, int column, int roomNum){
//printRoomNumArray();
if (roomNumArray[row][column] != 0)
return;
roomNumArray[row][column] = roomNum;
roomSize[roomNum]++;
int directionIndex;
for (directionIndex = 0; directionIndex < 4; directionIndex++){
int x = row + directionArray[directionIndex][0];
int y = column + directionArray[directionIndex][1];
if (x >= 0 && x < numOfRows && y >= 0 && y < numOfColumns && wall[row][column][directionIndex] != 1 && roomNumArray[x][y] == 0)
numberRoom(x, y, roomNum);
}
}

int main(){
#if DEBUG
int testCase;
for (testCase = 1; testCase <= TESTCASES; testCase++){
char inputFileName[20] = "inputx.txt";
inputFileName[5] = '1' +  (testCase - 1);
freopen(inputFileName, "r", stdin);
printf("\n#%d\n", testCase);
#endif

scanf("%d%d", &numOfColumns, &numOfRows);
int row, column;
for (row = 0; row < numOfRows; row++)
for (column = 0; column < numOfColumns; column++){
int num;
scanf("%d", &num);
int direction;
for (direction = 0; direction < 4; direction++)
wall[row][column][direction] = (num >> direction) & 1;
}

int roomNum = 1;
for (row = 0; row < numOfRows; row++)
for (column = 0; column < numOfColumns; column++){
roomSize[roomNum++] = 0;
roomNumArray[row][column] = 0;
}

int maxRoomSize = 0;
roomNum = 0;
for (row = 0; row < numOfRows; row++)
for (column = 0; column < numOfColumns; column++)
if (roomNumArray[row][column] == 0){
numberRoom(row, column, ++roomNum);
if (roomSize[roomNum] > maxRoomSize)
maxRoomSize = roomSize[roomNum] ;
}

printf("%d\n%d\n", roomNum, maxRoomSize);

int roomSizeCreated = 0;
int maxRoomSizeCreated = 0;
int rowToRemove = -1, columnToRemove = -1;
char directionOfWallRemoved = '0';
for (column = 0; column < numOfColumns; column++)
for (row = numOfRows - 1; row >= 0; row--){
int currentRoomNum =  roomNumArray[row][column];

int eastColumn;
if ((eastColumn = column + 1) < numOfColumns){
int eastRoomNum = roomNumArray[row][eastColumn];
if (currentRoomNum != eastRoomNum)
if ( (roomSizeCreated = roomSize[eastRoomNum] + roomSize[currentRoomNum]) > maxRoomSizeCreated){
maxRoomSizeCreated = roomSizeCreated;
rowToRemove = row;
columnToRemove = column;
directionOfWallRemoved = 'E';
}

}
int northRow;
if ((northRow = row - 1) >= 0){
int northRoomNum = roomNumArray[northRow][column];
if (northRoomNum != currentRoomNum)
if ( (roomSizeCreated = roomSize[northRoomNum] + roomSize[currentRoomNum]) > maxRoomSizeCreated){
maxRoomSizeCreated = roomSizeCreated;
rowToRemove = row;
columnToRemove = column;
directionOfWallRemoved = 'N';
}
}
}

printf("%d\n%d %d %c\n", maxRoomSizeCreated, rowToRemove + 1, columnToRemove + 1, directionOfWallRemoved);

#if DEBUG
}
#endif
return 0;
}