【算法题】贪吃蛇

水深无声 2024-03-27 11:07 72阅读 0赞

### [贪吃蛇][Link 1] ###

![在这里插入图片描述][ef23db19633743cfa7dbf82256390e5d.png]

package logic;
    
    import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.util.Arrays;
    import java.util.Deque;
    import java.util.LinkedList;
    
    import static java.lang.System.in;
    
    /**
     * 贪吃蛇
     * R G G
     * 3 3
     * F F F
     * F F H
     * E F E
     */
    public class GluttonousSnake {
        
        public static void main(String[] args) throws IOException {
        
            // 读取数据源
            BufferedReader bf = new BufferedReader(new InputStreamReader(in));
            // 收集操作
            char[] actions = bf.readLine().replaceAll(" ", "").toCharArray();
    
            // 读取方格大小
            int[] size = Arrays.stream(bf.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
            int x = size[0];
            int y = size[1];
    
            // 填充方格
            char[][] map = new char[x][y];
            for (int i = 0; i < x; i++) {
        
                char[] s = bf.readLine().replaceAll(" ", "").toCharArray();
                map[i] = s;
            }
            bf.close();
    
            // 贪吃蛇身体
            Deque<int[]> body = new LinkedList<>();
    
            // 找到蛇头
            for (int i = 0; i < x; i++) {
        
                for (int j = 0; j < y; j++) {
        
                    if (map[i][j] == 'H') {
        
                        body.offerLast(getLocation(i, j));
                        break;
                    }
                }
            }
    
            // 业务逻辑处理
            char tempAction = 0;
            for (Character action : actions) {
        
                int[] ints = body.peekFirst().clone();
                if ('U' == action) {
        
                    tempAction = 'U';
                } else if ('D' == action) {
        
                    tempAction = 'D';
                } else if ('L' == action) {
        
                    tempAction = 'L';
                } else if ('R' == action) {
        
                    tempAction = 'R';
                } else if ('G' == action) {
        
                    if ('U' == tempAction) {
        
                        ints[0]--;
                    } else if ('D' == tempAction) {
        
                        ints[0]++;
                    } else if ('L' == tempAction) {
        
                        ints[1]--;
                    } else if ('R' == tempAction) {
        
                        ints[1]++;
                    }
    
                    // 出界停止后续操作
                    if (!isValid(map, ints[0], ints[1], body)) {
        
                        break;
                    }
    
                    // 如果为食物，只吃不减
                    if (map[ints[0]][ints[1]] == 'F') {
        
                        body.addFirst(getLocation(ints[0], ints[1]));
                    } else {
        
                        // 没迟到食物则，加头去尾
                        body.addFirst(getLocation(ints[0], ints[1]));
                        body.removeLast();
                    }
                }
    
            }
    
            // 贪吃蛇的长度
            System.out.println(body.size());
        }
    
        public static boolean isValid(char[][] map, int i, int j, Deque<int[]> body) {
        
            boolean isValid = true;
            // 判断是否在方格内
            if (!(0 <= i && i < map.length && 0 <= j && j < map[i].length)) {
        
                return false;
            }
    
            // 判断是否撞到自己了
            for (int[] ints : body) {
        
                if (ints[0] == i && ints[1] == j) {
        
                    return false;
                }
            }
            return isValid;
        }
    
        public static int[] getLocation(int i, int j) {
        
            return new int[]{
        i, j};
        }
    }

[Link 1]: https://blog.nowcoder.net/n/42420d1a2d324c32838f7f23e4da45f3
[ef23db19633743cfa7dbf82256390e5d.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/27/ab64643b68e641f79efd3284d22dfaf1.png