DFS plus BFS之“Children of the Candy Corn”

  1 import java.util.*;
  2 
  3 public class Main{
  4 
  5     static char map[][] = new char[50][50];
  6     static int mark[][] = new int[50][50];
  7     static int cnt[][] = new int[50][50];
  8     static int m; 
  9     static int n;
 10     static int op_x;
 11     static int op_y;
 12     static int ed_x;
 13     static int ed_y;
 14     static int temp;
 15     static int bfs_ans;
 16 
 17     static int L[][] = {{0,1},{1,0},{0,-1},{-1,0}};
 18     static int R[][] = {{0,-1},{1,0},{0,1},{-1,0}};
 19 
 20     static int dfs_L(int x,int y,int step){
 21         if(x == ed_x && y == ed_y) return step + 1;
 22         if(x < 1 || x > n || y < 1 || y > m || map[x][y] == ‘#‘) return 0;
 23         temp = (temp + 3) % 4;
 24         int out = 0;
 25         int flag = 0;
 26         while(flag == 0){
 27             out = dfs_L(x + L[temp][0],y + L[temp][1],step + 1);
 28             if(out > 0) break;
 29             temp = (temp + 1) % 4;
 30         }
 31         return out;
 32     }
 33 
 34     static int dfs_R(int x,int y,int step){
 35         if(x == ed_x && y == ed_y) return step + 1;
 36         if(x < 1 || x > n || y < 1 || y > m || map[x][y] == ‘#‘) return 0;
 37         temp = (temp + 3) % 4;
 38         int out = 0;
 39         int flag = 0;
 40         while(flag == 0){
 41             out = dfs_R(x + R[temp][0],y + R[temp][1],step + 1);
 42             if(out > 0) break;
 43             temp = (temp + 1) % 4;
 44         }
 45         return out;
 46     }
 47 
 48     static void bfs(int x,int y){
 49         Queue<Integer> que = new LinkedList<Integer>();
 50         que.offer(x); que.offer(y);
 51         int t1; int t2;
 52         while(que.size() != 0){
 53             t1 = que.peek(); que.poll();
 54             t2 = que.peek(); que.poll();
 55             if(mark[t1][t2] == -1) {continue;}
 56             if(t1 == ed_x && t2 == ed_y){
 57                 bfs_ans = cnt[t1][t2];
 58                 return ;
 59             }
 60             mark[t1][t2] = -1;
 61             if(t1 >= 1 && t1 <= n && t2 >= 1 && t2 <= m){
 62                 if(t1 >= 2 && map[t1 - 1][t2] != ‘#‘){
 63                     que.offer(t1 - 1);
 64                     que.offer(t2);
 65                     cnt[t1 - 1][t2] = cnt[t1][t2] + 1;
 66                 }
 67                 if(t1 <= n - 1 && map[t1 + 1][t2] != ‘#‘){
 68                     que.offer(t1 + 1);
 69                     que.offer(t2);
 70                     cnt[t1 + 1][t2] = cnt[t1][t2] + 1;
 71                 }
 72                 if(t2 >= 2 && map[t1][t2 - 1] != ‘#‘){
 73                     que.offer(t1);
 74                     que.offer(t2 - 1);
 75                     cnt[t1][t2 - 1] = cnt[t1][t2] + 1;
 76                 }
 77                 if(t2 <= m - 1 && map[t1][t2 + 1] != ‘#‘){
 78                     que.offer(t1);
 79                     que.offer(t2 + 1);
 80                     cnt[t1][t2 + 1] = cnt[t1][t2] + 1;
 81                 }
 82             }
 83         }
 84         return ;
 85     }
 86 
 87     public static void main(String[] args){
 88         Scanner sc = new Scanner(System.in);
 89         int t = sc.nextInt();
 90         while(t > 0){
 91             m = sc.nextInt();
 92             n = sc.nextInt();
 93             String enter = sc.nextLine();
 94             for(int i = 1;i <= n;i ++){
 95                 String in = sc.nextLine();
 96                 for(int j = 1;j <= m;j ++){
 97                     map[i][j] = in.charAt(j - 1);
 98                     if(map[i][j] == ‘S‘){op_x = i;op_y = j;}
 99                     if(map[i][j] == ‘E‘){ed_x = i;ed_y = j;}
100                 }
101             }
102             for(int i = 1;i <= m;i ++){
103                 for(int j = 1;j <= n;j ++){
104                     mark[j][i] = 0;
105                     cnt[j][i] = 0;
106                 }
107             }
108             System.out.print(dfs_L(op_x,op_y,0) + " ");
109             System.out.print(dfs_R(op_x,op_y,0) + " ");
110             bfs(op_x,op_y);
111             System.out.println(bfs_ans + 1);
112             
113             t --;
114         }
115     }
116 }