1 #include<cstdio> 2 #include<cstring> 3 int sx[4]={0,1,0,-1}; 4 int sy[4]={1,0,-1,0}; 5 int g[10][10]; 6 int x1,y1,x2,y2; 7 int step; 8 int n,m,t; 9 void dfs(int x,int y,int c_step) 10 { 11 12 if(x==x2&&y==y2&&c_step==t) 13 { 14 15 step=1;return; 16 } 17 if((x>x2?x-x2:x2-x)+(y>y2?y-y2:y2-y)+c_step>t)//小剪 18 { 19 return; 20 } 21 int i; 22 for(i=0;i<4;i++) 23 { 24 int xx,yy; 25 xx=x+sx[i]; 26 yy=y+sy[i]; 27 if(xx>=1&&xx<=n&&yy>=1&&yy<=m&&g[xx][yy]==0&&c_step+1<=t) 28 { 29 g[xx][yy]=1; 30 dfs(xx,yy,c_step+1); 31 if(step==1)//强力缩短时间 32 return; 33 g[xx][yy]=0; 34 } 35 } 36 37 } 38 int main() 39 { 40 int i,j,sum; 41 char c; 42 while(scanf("%d %d %d",&n,&m,&t)!=EOF) 43 { 44 if(!n&&!m&&!t)break; 45 step=0; 46 sum=0; 47 getchar(); 48 for(i=1;i<=n;i++) 49 { 50 for(j=1;j<=m;j++) 51 { 52 c=getchar(); 53 if(c=='S') 54 x1=i,y1=j; 55 else if(c=='D') 56 x2=i,y2=j,g[i][j]=0; 57 else if(c=='X') 58 g[i][j]=1; 59 else if(c=='.') 60 g[i][j]=0,sum++; 61 } 62 getchar(); 63 } 64 if(sum+1<t||(t+x1+y1+x2+y2)%2==1)//奇偶性判别与可达性判别 65 printf("NO "); 66 else 67 { 68 g[x1][y1]=1; 69 dfs(x1,y1,0); 70 if(step) 71 printf("YES "); 72 else 73 printf("NO "); 74 } 75 } 76 return 0; 77 }