蓝桥杯 最短路径问题

 1 import java.util.*;
 2 
 3 public class Main{
 4     private class Point {
 5         int x = 0;
 6         int y = 0;
 7 
 8         public Point() {
 9             this(0, 0);
10         }
11 
12         public Point(int x, int y) {
13             this.x = x;
14             this.y = y;
15         }
16 
17         public boolean equals(Point p) {
18             return (this.x == p.x) && (this.y == p.y); // 填入第1行代码 完成点与点的比较
19         }
20 
21         public String toString() {
22             return "(" + x + ", " + y + ")";
23         }
24     }
25 
26     private int[][] maze = null;
27     private Stack<Point> stack = new Stack<Point>();
28 
29     public Main(int[][] maze) {
30         this.maze = maze;
31     }
32 
33     public void go() {
34         Point out = new Point(maze.length - 1, maze[0].length - 1);
35         Point in = new Point(0, 0);
36         Point curNode = in;
37         Point nextNode = null;
38         while (!curNode.equals(out)) {
39 
40             nextNode = new Point(curNode.x, curNode.y);
41 
42             if ((nextNode.x+1<maze.length)&&(maze[curNode.x+1][curNode.y] == 0)) { // 填入第2行代码
43                 nextNode.x++;
44             } else if ((nextNode.y+1<maze[0].length)&&(maze[curNode.x][curNode.y+1] == 0)) { // 填入第3行代码
45                 nextNode.y++;
46             } else if ((nextNode.x-1>=0)&&(maze[curNode.x-1][curNode.y] == 0)) { // 填入第4行代码
47                 nextNode.x--;
48             } else if ((nextNode.y-1>=0)&&(maze[curNode.x][curNode.y-1] == 0)) { // 填入第5行代码
49                 nextNode.y--;
50             } else {
51                 maze[curNode.x][curNode.y] = 3;
52                 if (stack.isEmpty()) {
53                     System.out.println("Non solution");
54                     return;
55                 }
56                 curNode = stack.pop();
57                 continue;
58             }
59             stack.push(curNode);
60             maze[curNode.x][curNode.y] = 2;
61             curNode = nextNode;
62         }
63 
64         if (nextNode.equals(out)) {
65             stack.push(nextNode);
66             maze[nextNode.x][nextNode.y] = 2;
67         }
68         for (int i = 0; i < stack.size(); i++)
69             System.out.println(stack.elementAt(i));
70     }
71 
72     public static void main(String[] args) {
73         int[][] maze = { { 0, 1, 0, 0, 0 }, { 0, 1, 0, 1, 0 }, { 0, 0, 0, 0, 0 }, { 0, 1, 1, 1, 0 },
74                 { 0, 0, 0, 1, 0 } };
75         new Main(maze).go();
76     }
77 }