1    package bookExamples.ch08ArraysAndVectors.maze; 
2     
3     
4    public class MazeUtility { 
5        private final static int right = 1, left = 3, up = 2, down = 0; 
6        private static int w = 0; 
7        private static int h = 0; 
8     
9        private static String mazeString[] = null; 
10       private static char maze[][] = null; 
11    
12       public static void setMazeString(String ms[]) { 
13           mazeString = ms; 
14           maze = getChars(mazeString); 
15       } 
16    
17       public void setMaze(char c[][]) { 
18           maze = c; 
19       } 
20    
21    
22       public static char[][] getChars(String s[]) { 
23           char c[][] = new char[s.length][s[0].length()]; 
24           for (int r = 0; r < s.length; r++) 
25               s[r].getChars(0, s[0].length(), c[r], 0); 
26    
27           return c; 
28       } 
29    
30       public static void print() { 
31           char c[][] = maze; 
32           for (int r = 0; r < c.length; r++) { 
33               for (int col = 0; col < c[r].length; col++) 
34                   System.out.print(c[r][col]); 
35               System.out.println(); 
36           } 
37       } 
38    
39       public static java.awt.Point getStart() { 
40           for (int r = 0; r < maze.length; r++) 
41               for (int c = 0; c < maze[0].length; c++) 
42                   if (maze[r][c] == 'S') 
43                       return new java.awt.Point(r, c); 
44           return new java.awt.Point(0, 0); 
45       } 
46    
47       public static java.awt.Point getExit() { 
48           return new java.awt.Point(6, 16); 
49       } 
50    
51       public static void markExit(java.awt.Point p) { 
52           maze[p.x][p.y] = 'E'; 
53       } 
54    
55       public static boolean isDone( 
56               char maze[][], 
57               java.awt.Point p) { 
58           return maze[p.x][p.y] == 'E'; 
59       } 
60    
61       public static void markStart( 
62               java.awt.Point p) { 
63           maze[p.x][p.y] = 'S'; 
64       } 
65    
66       public static void mark(java.awt.Point p) { 
67           maze[p.x][p.y] = 'X'; 
68       } 
69    
70       public static void solve() { 
71           java.awt.Point start = getStart(); 
72           //System.out.println("Start="+start); 
73           //Point exit = getExit(); 
74           //System.out.println("Exit="+exit); 
75           //markStart( start); 
76           //markExit(exit); 
77           mazeTraverse(start, left); 
78       } 
79    
80       public static void mazeTraverse(java.awt.Point loc, int direction) { 
81           if (isDone(maze, loc)) { 
82               System.out.println("I am done!"); 
83               return; 
84           } 
85           w = maze.length; 
86           h = maze[0].length; 
87           int x = loc.x; 
88           int y = loc.y; 
89           mark(loc); 
90           for (int move = direction, count = 0; count < 4; ++count, ++move, move %= 4) { 
91               switch (move) { 
92                   case down: 
93                       if (validMove(x + 1, y)) { 
94                           mazeTraverse(new java.awt.Point(x + 1, y), left); 
95                           return; 
96                       } 
97                       break; 
98                   case right: 
99                       if (validMove(x, y + 1)) { 
100                          mazeTraverse(new java.awt.Point(x, y + 1), down); 
101                          return; 
102                      } 
103                      break; 
104                  case up: 
105                      if (validMove(x - 1, y)) { 
106                          mazeTraverse(new java.awt.Point(x - 1, y), right); 
107                          return; 
108                      } 
109                      break; 
110                  case left: 
111                      if (validMove(x, y - 1)) { 
112                          mazeTraverse(new java.awt.Point(x, y - 1), up); 
113                          return; 
114                      } 
115                      break; 
116              } 
117   
118          } 
119      } 
120   
121      public static boolean validMove(int r, int c) { 
122          return (r >= 0 && r <= w && c >= 0 && c < h && maze[r][c] != '#'); 
123      } 
124   
125      public static int getRight() { 
126          return right; 
127      } 
128   
129      public static int getLeft() { 
130          return left; 
131      } 
132   
133      public static int getUp() { 
134          return up; 
135      } 
136   
137      public static int getDown() { 
138          return down; 
139      } 
140   
141      public static int getW() { 
142          return w; 
143      } 
144   
145      public static void setW(int w) { 
146          MazeUtility.w = w; 
147      } 
148   
149      public static int getH() { 
150          return h; 
151      } 
152   
153      public static void setH(int h) { 
154          MazeUtility.h = h; 
155      } 
156   
157      public static String[] getMazeString() { 
158          return mazeString; 
159      } 
160   
161      public static char[][] getMaze() { 
162          return maze; 
163      } 
164   
165  }