poj 2386

题意：给你一个row*col的矩阵表示一块田地，上面的'W'代表积水，'.'表示干地，问这块田地里面的积水能汇聚成几片水洼

简单的dfs,由于粗心，水和田搞反了，wa了好几次

Memory: 3848K

Time: 1500MS

 1 import java.util.Scanner;

 2 

 3 public class Main{

 4     static char map[][];

 5     static int n,m;

 6     static boolean visited[][];

 7     static int move[][] = {{0,0,1,-1,1,1,-1,-1},{1,-1,0,0,1,-1,1,-1}};

 8     

 9     public static boolean isIn(int x,int y){

10         return x>=0&&x<n&&y>=0&&y<m;

11     }

12     

13     public static void dfs(int x,int y){

14         visited[x][y] = true;

15         for(int i=0;i<8;i++){

16             int tx = x + move[0][i];

17             int ty = y + move[1][i];

18             if(isIn(tx,ty)&&map[tx][ty]!='.'&&visited[tx][ty]==false)

19                 dfs(tx,ty);

20         }

21     }

22     

23     public static void main(String[] args){

24         Scanner in = new Scanner(System.in);

25         n = in.nextInt();

26         m = in.nextInt();

27         in.nextLine();

28         map = new char[n][m];

29         visited = new boolean[n][m];

30         for(int i=0;i<n;i++){

31             map[i] = in.nextLine().trim().toCharArray();

32         }

33         int num=0;

34         for(int i=0;i<n;i++){

35             for(int j=0;j<m;j++){

36                 if(map[i][j]=='W'&&visited[i][j]==false)

37                 {

38                     dfs(i,j);

39                     num++;

40                 }

41             }

42         }

43         System.out.print(num);

44     }

45 }