240810 가스관

private static int rows;
private static int cols;
private static char[][] map;
private static final int[] dx = {-1, 1, 0, 0};
private static final int[] dy = {0, 0, -1, 1};
private static final int TOP = 0;
private static final int BOTTOM = 1;
private static final int LEFT = 2;
private static final int RIGHT = 3;

public static void main(String[] args) throws IOException {
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	String[] dimensions = br.readLine().split(" ");
	rows = Integer.parseInt(dimensions[0]);
	cols = Integer.parseInt(dimensions[1]);
	map = new char[rows][cols];

	for (int i = 0; i < rows; i++) {
		map[i] = br.readLine().toCharArray();
	}

	for (int i = 0; i < rows; i++) {
		for (int j = 0; j < cols; j++) {
			if (map[i][j] == '.' && checkPipe(i, j)) {
				return;
			}
		}
	}
}

private static boolean checkPipe(int x, int y) {
	boolean[] connected = new boolean[4];
	connected[TOP] = isInRange(x + dx[TOP], y + dy[TOP]) && canComeFromBottom(map[x + dx[TOP]][y + dy[TOP]]);
	connected[BOTTOM] = isInRange(x + dx[BOTTOM], y + dy[BOTTOM]) && canComeFromTop(map[x + dx[BOTTOM]][y + dy[BOTTOM]]);
	connected[LEFT] = isInRange(x + dx[LEFT], y + dy[LEFT]) && canComeFromRight(map[x + dx[LEFT]][y + dy[LEFT]]);
	connected[RIGHT] = isInRange(x + dx[RIGHT], y + dy[RIGHT]) && canComeFromLeft(map[x + dx[RIGHT]][y + dy[RIGHT]]);

	if (connected[TOP] && connected[BOTTOM] && connected[LEFT] && connected[RIGHT])
		System.out.println((x + 1) + " " + (y + 1) + " +");
	else if (connected[TOP] && connected[BOTTOM])
		System.out.println((x + 1) + " " + (y + 1) + " |");
	else if (connected[TOP] && connected[LEFT])
		System.out.println((x + 1) + " " + (y + 1) + " 3");
	else if (connected[TOP] && connected[RIGHT])
		System.out.println((x + 1) + " " + (y + 1) + " 2");
	else if (connected[BOTTOM] && connected[LEFT])
		System.out.println((x + 1) + " " + (y + 1) + " 4");
	else if (connected[BOTTOM] && connected[RIGHT])
		System.out.println((x + 1) + " " + (y + 1) + " 1");
	else if (connected[LEFT] && connected[RIGHT])
		System.out.println((x + 1) + " " + (y + 1) + " -");
	else
		return false;

	return true;
}

private static boolean isInRange(int x, int y) {
	return 0 <= x && x < rows && 0 <= y && y < cols;
}

private static boolean canComeFromTop(char c) {
	return c == '|' || c == '+' || c == '2' || c == '3';
}

private static boolean canComeFromBottom(char c) {
	return c == '|' || c == '+' || c == '1' || c == '4';
}

private static boolean canComeFromLeft(char c) {
	return c == '-' || c == '+' || c == '3' || c == '4';
}

private static boolean canComeFromRight(char c) {
	return c == '-' || c == '+' || c == '1' || c == '2';
}

출처:https://www.acmicpc.net/problem/2931