241120 새로운 게임 2

static int n, k;
static int[][] board;
static int[] directions;
static int[] positions;
static int[] dx = { 0, 0, -1, 1 };
static int[] dy = { 1, -1, 0, 0 };
static List<Integer>[][] stacks;

@SuppressWarnings("unchecked")
public static void main(String[] args) throws Exception {
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	String[] tokens = br.readLine().split(" ");
	n = Integer.parseInt(tokens[0]);
	k = Integer.parseInt(tokens[1]);
	board = new int[n][n];
	directions = new int[k + 1];
	positions = new int[k + 1];
	stacks = new List[n][n];

	for (int i = 0; i < n; i++) {
		tokens = br.readLine().split(" ");
		for (int j = 0; j < n; j++) {
			board[i][j] = Integer.parseInt(tokens[j]);
		}
	}

	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			stacks[i][j] = new ArrayList<>();
		}
	}

	for (int i = 0; i < k; i++) {
		tokens = br.readLine().split(" ");
		int row = Integer.parseInt(tokens[0]) - 1;
		int col = Integer.parseInt(tokens[1]) - 1;
		int dir = Integer.parseInt(tokens[2]) - 1;
		directions[i + 1] = dir;
		positions[i + 1] = row * n + col;
		stacks[row][col].add(i + 1);
	}

	int turn = 1;
	while (turn <= 1000) {
		for (int i = 0; i < k; i++) {
			int piece = i + 1;
			int dir = directions[piece];
			int x = positions[piece] / n;
			int y = positions[piece] % n;
			int nx = x + dx[dir];
			int ny = y + dy[dir];
			int stackSize = stacks[x][y].size();

			if (!isValid(nx, ny) || board[nx][ny] == 2) {
				dir = reverseDirection(dir);
				directions[piece] = dir;
				nx = x + dx[dir];
				ny = y + dy[dir];
			}

			if (isValid(nx, ny)) {
				if (board[nx][ny] == 1) {
					moveRed(x, y, nx, ny, piece, stackSize);
				} else if (board[nx][ny] == 0) {
					moveWhite(x, y, nx, ny, piece, stackSize);
				}
				if (stacks[nx][ny].size() > 3) {
					System.out.println(turn);
					return;
				}
			}
		}
		turn++;
	}
	System.out.println(-1);
}

static void moveRed(int x, int y, int nx, int ny, int piece, int stackSize) {
	for (int i = stackSize - 1; i >= 0; i--) {
		int currPiece = stacks[x][y].get(i);
		stacks[nx][ny].add(currPiece);
		stacks[x][y].remove(i);
		positions[currPiece] = nx * n + ny;
		if (currPiece == piece)
			break;
	}
}

static void moveWhite(int x, int y, int nx, int ny, int piece, int stackSize) {
	for (int i = 0; i < stackSize; i++) {
		int currPiece = stacks[x][y].get(i);
		if (currPiece == piece) {
			while (i < stacks[x][y].size()) {
				currPiece = stacks[x][y].get(i);
				stacks[nx][ny].add(currPiece);
				stacks[x][y].remove(i);
				positions[currPiece] = nx * n + ny;
			}
			break;
		}
	}
}

static boolean isValid(int x, int y) {
	return x >= 0 && y >= 0 && x < n && y < n;
}

static int reverseDirection(int dir) {
	if (dir == 0)
		return 1;
	if (dir == 1)
		return 0;
	if (dir == 2)
		return 3;
	return 2;
}

출처:https://www.acmicpc.net/problem/17837