Design Sanke Game

 1 public class SnakeGame {
 2     private Deque<Integer> snake;
 3     private int[][] food;
 4     private int width;
 5     private int height;
 6     private boolean isGameOver;
 7     private int index;
 8
 9     /** Initialize your data structure here.
10         @param width - screen width
11         @param height - screen height
12         @param food - A list of food positions
13         E.g food = [[1,1], [1,0]] means the first food is positioned at [1,1], the second is at [1,0]. */
14     public SnakeGame(int width, int height, int[][] food) {
15         this.food = food;
16         this.width = width;
17         this.height = height;
18         snake = new LinkedList<>();
19         snake.offer(0);
20         isGameOver = false;
21         index = 0;
22     }
23
24     /** Moves the snake.
25         @param direction - ‘U‘ = Up, ‘L‘ = Left, ‘R‘ = Right, ‘D‘ = Down
26         @return The game‘s score after the move. Return -1 if game over.
27         Game over when snake crosses the screen boundary or bites its body. */
28     public int move(String direction) {
29         if (isGameOver) {
30             return -1;
31         }
32         int head = snake.getFirst();
33         int tail = snake.pollLast();
34         int x = head / width;
35         int y = head % width;
36
37         switch (direction) {
38             case "U":
39                 x--;
40                 break;
41             case "D":
42                 x++;
43                 break;
44             case "L":
45                 y--;
46                 break;
47             case "R":
48                 y++;
49                 break;
50         }
51
52         if (x < 0 || x >= height || y < 0 || y >= width || snake.contains(x*width + y)) {
53             isGameOver = true;
54             return -1;
55         }
56         snake.addFirst(x*width + y);
57         if (index < food.length && food[index][0] == x && food[index][1] == y) {
58             index++;
59             snake.offer(tail);
60         }
61         return snake.size() - 1;
62     }
63 }
64
65 /**
66  * Your SnakeGame object will be instantiated and called as such:
67  * SnakeGame obj = new SnakeGame(width, height, food);
68  * int param_1 = obj.move(direction);
69  */

1. The score got is not original size of snake since starting score is 0 when snake size is 1.

2. Do not forget to add the head after check death.