hdu1198 Farm Irrigation —— dfs or 并查集

 1 #include<cstdio>//hdu1198 dfs
 2 #include<cstring>
 3 
 4 int well[11][5] = { {1,1,1,0,0},{1,0,1,1,0},{0,1,1,0,1},{0,0,1,1,1},{1,0,1,0,1},{0,1,1,1,0},{1,1,1,1,0},{1,1,1,0,1},{0,1,1,1,1},{1,0,1,1,1},{1,1,1,1,1}};
 5 
 6 const int ca[5][2] = {0,1,1,0,1,1,1,2,2,1}, mov[4][2] = {1,0,-1,0,0,1,0,-1};
 7 int m,n,sum, map[550][550],id[550][550];
 8 
 9 void build(int set, int x, int y)
10 {
11     for(int k = 0; k<5; k++)
12     {
13         if(well[set][k])
14         {
15             map[3*x+ca[k][0]][3*y+ca[k][1]] = 1;
16         }
17     }
18 }
19 
20 void dfs(int x, int y, int iden)
21 {
22     id[x][y] = iden;
23     for(int i = 0; i<4; i++)
24     {
25         int xx = x + mov[i][0], yy = y + mov[i][1];
26         if(xx<0 || xx>3*m-1 || yy<0 || yy>3*n-1 ) continue;
27         if(map[xx][yy] && !id[xx][yy])
28         dfs(xx,yy,iden);
29     }
30 }
31 
32 int main()
33 {
34     char init[5005];
35     while(scanf("%d%d",&m,&n) && (m!=-1 || n!=-1 ))
36     {
37         memset(map,0,sizeof(map));
38         memset(id,0,sizeof(id));
39         for(int i = 0; i<m; i++)
40         {
41             scanf("%s",init);
42             for(int j = 0; j<n; j++)
43             build(init[j]-65,i,j);
44         }
45         sum = 0;
46         for(int i = 0; i<=3*m-1; i++)
47         {
48 
49             for(int j = 0; j<=3*n-1; j++)
50             {
51                 //printf("%d ",map[i][j]);
52                 if(map[i][j] && !id[i][j])
53                 {
54                     dfs(i,j,++sum);
55                 }
56             }
57             //putchar('
');
58         }
59 
60         printf("%d
",sum);
61 
62     }
63     return 0;
64 }