import java.util.*;

public class MazeSolver {
    private static final int ROWS = 15;
    private static final int COLS = 25;
    private static final char WALL = '█';
    private static final char PATH = ' ';
    private static final char START = 'S';
    private static final char END = 'E';
    private static final char SOLUTION = '·';
    private char[][] maze;
    private boolean[][] visited;
    private int startRow, startCol, endRow, endCol;
    public MazeSolver() {
        maze = new char[ROWS][COLS];
        visited = new boolean[ROWS][COLS];
        generateMaze();
    }
    private void generateMaze() {
        for (int i = 0; i < ROWS; i++) {
            for (int j = 0; j < COLS; j++) {
                maze[i][j] = WALL;
            }
        }
        Random rand = new Random();
        Stack<int[]> stack = new Stack<>();
        startRow = 1;
        startCol = 1;
        maze[startRow][startCol] = PATH;
        stack.push(new int[]{startRow, startCol});
        int[][] directions = {{-2, 0}, {2, 0}, {0, -2}, {0, 2}};
        while (!stack.isEmpty()) {
            int[] current = stack.peek();
            int row = current[0];
            int col = current[1];
            List<int[]> neighbors = new ArrayList<>();
            for (int[] dir : directions) {
                int newRow = row + dir[0];
                int newCol = col + dir[1];

                if (newRow > 0 && newRow < ROWS - 1 &&
                        newCol > 0 && newCol < COLS - 1 &&
                        maze[newRow][newCol] == WALL) {
                    neighbors.add(new int[]{newRow, newCol, row + dir[0]/2, col + dir[1]/2});
                }
            }
            if (!neighbors.isEmpty()) {
                int[] next = neighbors.get(rand.nextInt(neighbors.size()));
                maze[next[2]][next[3]] = PATH; // Rompi il muro
                maze[next[0]][next[1]] = PATH;
                stack.push(new int[]{next[0], next[1]});
            } else {
                stack.pop();
            }
        }
        endRow = ROWS - 2;
        endCol = COLS - 2;
        maze[startRow][startCol] = START;
        maze[endRow][endCol] = END;
    }

    private void printMaze() {
        System.out.println("\n╔" + "═".repeat(COLS) + "╗");
        for (int i = 0; i < ROWS; i++) {
            System.out.print("║");
            for (int j = 0; j < COLS; j++) {
                System.out.print(maze[i][j]);
            }
            System.out.println("║");
        }
        System.out.println("╚" + "═".repeat(COLS) + "╝");
    }

    private boolean solveMaze(int row, int col, List<int[]> path) {
        if (row < 0 || row >= ROWS || col < 0 || col >= COLS) {
            return false;
        }

        if (maze[row][col] == WALL || visited[row][col]) {
            return false;
        }
        visited[row][col] = true;
        path.add(new int[]{row, col});
        if (row == endRow && col == endCol) {
            return true;
        }
        if (solveMaze(row - 1, col, path) ||
                solveMaze(row + 1, col, path) ||
                solveMaze(row, col - 1, path) ||
                solveMaze(row, col + 1, path)) {
            return true;
        }
        path.remove(path.size() - 1);
        return false;
    }
    private void markSolution(List<int[]> path) {
        for (int[] pos : path) {
            int row = pos[0];
            int col = pos[1];
            if (maze[row][col] != START && maze[row][col] != END) {
                maze[row][col] = SOLUTION;
            }
        }
    }
    public void solve() {
        System.out.println("LABIRINTO ORIGINALE:");
        printMaze();
        List<int[]> path = new ArrayList<>();
        visited = new boolean[ROWS][COLS];
        System.out.println("\nRisoluzione in corso...");
        if (solveMaze(startRow, startCol, path)) {
            markSolution(path);
            System.out.println("\nLABIRINTO RISOLTO:");
            printMaze();
            System.out.println("\nPercorso trovato! Lunghezza: " + path.size() + " passi");
        } else {
            System.out.println("\nNessuna soluzione trovata!");
        }
    }
    public static void main(String[] args) {
        System.out.println("=== GENERATORE E RISOLUTORE DI LABIRINTI ===");
        System.out.println("Legenda: " + START + " = Inizio, " + END + " = Fine, " +
                SOLUTION + " = Soluzione");
        MazeSolver solver = new MazeSolver();
        solver.solve();
    }
}