hdu 1010(Tempter of the Bone)

hdu 1010(Tempter of the Bone)

 1 #include <cstdio>
 2 #include <cstdlib>
 3 #include <cmath>
 4 #include <cstring>
 5  #define MAXSIZE 8
 6  char map[MAXSIZE][MAXSIZE];
 7  bool continues;
 8  int N,M,T;
 9  int a1,b1;
10  int a2,b2;
11  int ten[4][2]={
12         0,-1,
13         0,1,
14         1,0,
15         -1,0
16     };
17 inline  void trans( int &x, int &y, int times){    
18     x+=ten[times][0];
19     y+=ten[times][1];
20 }
21  void dfs( int x, int y, int t){
22      if(!continues||t==T)
23          return;
24      int dis=T-t-(abs(x-a2)+abs(y-b2));
25      if(dis<0||dis&1)
26          return ;
27      int p,q;
28      int times=0;
29      while (continues&&times<4){
30         p=x,q=y;
31         trans(p,q,times);
32         times++;
33          if(p<0||p>=N||q<0||q>=M)
34              continue;
35          if(map[p][q]=='D'&&t+1==T){
36             puts("YES");
37             continues= false;
38              return ;
39         }
40          if(map[p][q]=='.'){
41             map[p][q]='X';
42             dfs(p,q,t+1);
43              if(!continues)
44                  return ;
45             map[p][q]='.';
46         }    
47         
48     }
49 }
50 inline  void scan( char &ch){
51      while(ch=getchar())
52          if(ch=='.'||ch=='S'||ch=='D'||ch=='X')
53              break;
54 }
55  int main(){
56      // freopen("in.txt","r",stdin);
57       while (scanf("%d %d %d",&N,&M,&T)!=EOF,N||M||T){
58          int i,j,road=0;
59          for(i=0;i<N;i++)
60              for(j=0;j<M;j++){                
61                 scan(map[i][j]);
62                  if(map[i][j]=='.'){
63                     road++;
64                      continue;
65                 }
66                  if(map[i][j]=='S')
67                     a1=i,b1=j;
68                  if(map[i][j]=='D')
69                     a2=i,b2=j;
70             }
71          int dis=T-(abs(a1-a2)+abs(b1-b2));
72          if(road+1<T||dis<0||dis&1){
73             puts("NO");
74              continue;
75         }
76         continues= true;
77         dfs(a1,b1,0);
78          if (continues)
79             puts("NO");
80     }
81      return 0;
82 }
83