POJ 2386----Lake Counting (深搜)

这种题深搜和广搜都能做出来，个人感觉深搜比较好

还是提几点注意：

1.明白水塘在这个题中的定义

2.明白深搜和广搜的不同之处

Description

Due to recent rains, water has pooled in various places in Farmer John's field, which is represented by a rectangle of N x M (1 <= N <= 100; 1 <= M <= 100) squares. Each square contains either water ('W') or dry land ('.'). Farmer
John would like to figure out how many ponds have formed in his field. A pond is a connected set of squares with water in them, where a square is considered adjacent to all eight of its neighbors.

Given a diagram of Farmer John's field, determine how many ponds he has.

Input

* Line 1: Two space-separated integers: N and M

* Lines 2..N+1: M characters per line representing one row of Farmer John's field. Each character is either 'W' or '.'. The characters do not have spaces between them.

Output

* Line 1: The number of ponds in Farmer John's field.

Sample Input

10 12
W........WW.
.WWW.....WWW
....WW...WW.
.........WW.
.........W..
..W......W..
.W.W.....WW.
W.W.W.....W.
.W.W......W.
..W.......W.

Sample Output

3

#include<stdio.h>

#include<string.h>

int used[150][150]; //用来看元素是否被标记

char map[150][150];

int direction[8][2]={-1,0,0,-1,1,0,0,1,1,1,-1,-1,1,-1,-1,1}; //方向数组

int n,min,m,x,y,num;

void dfs(int x,int y)

{

int k,a,b;

used[x][y]=1;

for(k=0;k<8;k++)

{

a=x+direction[k][0];

b=y+direction[k][1];

if(a<n&&a>=0&&b<m&&b>=0&&used[a][b]==0&&map[a][b]=='W')

{

used[a][b]==1;

dfs(a,b); //递归

}

}

}

int main(void)

{

int i,j;

scanf("%d%d",&n,&m);

for(i=0;i<n;i++) scanf("%s",map[i]);

num=0;

memset(used,0,sizeof(used));

for(i=0;i<n;i++)

{

for(j=0;j<m;j++)

{

if(used[i][j]==0&&map[i][j]=='W')

{

dfs(i,j); //调用bfs主要是标记那些有水的地方！！！！

num++;

}

}

}

printf("%d\n",num);

return 0;

}