Miscellany

import java.io.*;

class MazeMarkPath {

    public static void main(String[] args) throws Exception {
        BufferedReader fin = new BufferedReader( new FileReader("DATAMAZE.txt"));
        main(fin);
        fin.close();
    }
    
    static char[][] maze;
    static int rows, cols;
    
    static final char EMPTY = '.';
    static final char MARKED = '#';
    static final char START = 'S';
    static final char END = 'E';
    static final char WALL = 'X';
    
    static int[] markx;
    static int[] marky;
    
    private static void main(BufferedReader fin) throws IOException {
        /*  getting input   */
        String temp = fin.readLine();
        rows = Integer.parseInt( temp.substring(0, temp.indexOf(' ') ) );
        cols = Integer.parseInt( temp.substring(temp.indexOf(' ') + 1));
        
        maze = new char[rows+2][cols+2];
        int startx = -1;
        int starty = -1;
        
        //top and bottom border
        for (int i = 0; i <maze[0].length; i++) {
            maze[0][i] = maze[maze.length - 1][i] = WALL;
        }
        for (int i = 1; i < maze.length - 1; i++) {
            temp = fin.readLine();
            maze[i][0] = maze[i][maze[0].length-1] = WALL;      //left and right border
            for (int j = 1; j < maze[0].length - 1; j++) {
                maze[i][j] = temp.charAt(j -1);
                if (maze[i][j] == START) {
                    startx = j;
                    starty = i;
                }
            }
        }
        
        markx = new int[rows * cols + 1];
        marky = new int[rows * cols + 1];
        for (int i = 0; i < markx.length; i++) {
            markx[i] = marky[i] = -1;
        }
        
        print(maze);
        System.out.println(starty + " "  + startx);
        System.out.println(findPath(startx, starty, 0));
        mark();
        print(maze);
    }
    
    private static int findPath(int x, int y, int depth) {
        if (maze[y][x] == END) {
            return 0;
        } else {
            if (maze[y][x] == EMPTY) {
                maze[y][x] = MARKED;
            }
            int min = rows * cols + 1;
            int temp;
            
            //up
            if (isOK( maze[y+1][x] ) ) {
                temp = findPath(x, y+1, depth+1);
                if (temp < min) {
                    min = temp;
                    markx[depth+1] = x;
                    marky[depth+1] = y+1;
                }
            }
            //down
            if (isOK( maze[y-1][x] ) ) {
                temp = findPath(x, y-1, depth+1);
                if (temp < min) {
                    min = temp;
                    markx[depth+1] = x;
                    marky[depth+1] = y-1;
                }
            }
            //right
            if (isOK( maze[y][x+1] ) ) {
                temp = findPath(x+1, y, depth+1);
                if (temp < min) {
                    min = temp;
                    markx[depth+1] = x+1;
                    marky[depth+1] = y;
                }
            }
            //left
            if (isOK( maze[y][x-1] ) ) {
                temp = findPath(x-1, y, depth+1);
                if (temp < min) {
                    min = temp;
                    markx[depth+1] = x-1;
                    marky[depth+1] = y;
                }
            }
            
            if (maze[y][x] == MARKED) {
                maze[y][x] = EMPTY;
            }
            return 1 + min;
        }
    }
    
    private static boolean isOK(char c) {
        return (c == EMPTY || c == END);
    }
    
    private static void mark() {
        for (int i = 1; markx[i] > 0; i++) {
            if (maze[marky[i]][markx[i]] == EMPTY)
                maze[marky[i]][markx[i]] = MARKED;
        }
    }
    
    private static void print(char[][] c) {
        for (int i = 0; i < c.length ;i++) {
            for (int j = 0; j < c[0].length ; j++) {
                System.out.print(c[i][j]);
            }
            System.out.println();
        }
    }
}