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hdu 1241 (Oil Deposits) legendary dfs

Problem link adress:http://acm.hdu.edu.cn/showproblem.php?pid=1241

These days I have encountered some problems when I was doing the searching problems;

May those problem need to use the DFS algorithm! So I started to learning the DFS:

Lots of friends says this probelm is a simple DFS problem, so I have a try on the problem!

Of course, I learned a lot from the "simple" problem!

View Code

 1 #include<iostream>
 2 #include<cstring>
 3 #include<queue>
 4 #include<cstdio>
 5 using namespace std;
 6 int mark[111][111];
 7 char map[105][105];
 8 int m,n;
 9 int dir[8][2]={0,1,0,-1,1,0,-1,0,1,-1,-1,1,1,1,-1,-1};
10 void DFS(int a,int b)
11 {
12     int x,y;
13     for(int i=0;i<8;i++)
14     {
15         x=a+dir[i][0];
16         y=b+dir[i][1];
17         if(x>=0&&x<m&&y>=0&&y<n&&mark[x][y]==0&&map[x][y]=='@')
18         {
19             mark[x][y]=1;
20             DFS(x,y);
21         }
22     }
23 }
24 
25 
26 int main()
27 {
28     int i,j;
29     while(cin>>m>>n)
30     {
31         getchar();
32         if(m==0) break;
33         for(i=0;i<m;i++)
34           for(j=0;j<n;j++)
35               cin>>map[i][j];
36         memset(mark,0,sizeof(mark));
37         int sum;
38         sum=0;
39         for(i=0;i<m;i++)
40             for(j=0;j<n;j++)
41             {
42                 if(map[i][j]=='@'&&mark[i][j]==0)
43                 {
44                     sum++;
45                     mark[i][j]=1;
46                     DFS(i,j);
47                 }
48             }
49             cout<<sum<<endl;
50     }
51     return 0;
52 }