Problem Description This is a simple game.The goal of the game is to roll two balls to two holes each.
'B' -- ball
'H' -- hole
'.' -- land
'*' -- wall
Remember when a ball rolls into a hole, they(the ball and the hole) disappeared, that is , 'H' + 'B' = '.'.
Now you are controlling two balls at the same time.Up, down , left , right --- once one of these keys is pressed, balls exist roll to that direction, for example , you pressed up , two balls both roll up.
A ball will stay where it is if its next point is a wall, and balls can't be overlap.
Your code should give the minimun times you press the keys to achieve the goal.
Input First there's an integer T(T<=100) indicating the case number.
Then T blocks , each block has two integers n , m (n , m <= 22) indicating size of the map.
Then n lines each with m characters.
There'll always be two balls(B) and two holes(H) in a map.
The boundary of the map is always walls(*).
Output The minimum times you press to achieve the goal.
Tell me "Sorry , sir , my poor program fails to get an answer." if you can never achieve the goal.
Sample Input
4
6 3
***
*B*
*B*
*H*
*H*
***
4 4
****
*BB*
*HH*
****
4 4
****
*BH*
*HB*
****
5 6
******
*.BB**
*.H*H*
*..*.*
******
Sample Output
3
1
2
Sorry , sir , my poor program fails to get an answer.
Author MadFroG
Source HDOJ Monthly Contest ? 2010.02.06
思路：普通的BFS，就是球移动的时候处理有点麻烦，要分还剩一个球和还剩两个球的情况考虑。
#include
#include
struct S{ int x[2],y[2],hx[2],hy[2],step,num; }que[1000000],t; int n,m; char mp[25][25]; bool vis[25][25][25][25]; int main() { int T,i,j,bf,hf; scanf("%d",&T); while(T--) { scanf("%d%d",&n,&m); for(i=1;i<=n;i++) scanf("%s",mp[i]+1); bf=hf=0; for(i=1;i<=n;i++) { for(j=1;j<=m;j++) { if(mp[i][j]=='B') { que[0].x[bf]=i; que[0].y[bf]=j; bf++; mp[i][j]='.'; } if(mp[i][j]=='H') { que[0].hx[hf]=i; que[0].hy[hf]=j; hf++; mp[i][j]='.'; } } } int top=0; int bottom=1; que[0].step=0; que[0].num=2; memset(vis,0,sizeof vis); while(top
=1 && mp[t.x[0]-1][t.y[0]]!='*') t.x[0]--; for(i=0;i<2;i++) if(t.hx[i]==t.x[0] && t.hy[i]==t.y[0]) { t.hx[i]=t.x[0]=0; t.num--; } if(t.x[1]-1>=1 &&mp[t.x[1]-1][t.y[1]]!='*' && !(t.x[1]-1==t.x[0] && t.y[1]==t.y[0])) t.x[1]--; for(i=0;i<2;i++) if(t.hx[i]==t.x[1] && t.hy[i]==t.y[1]) { t.hx[i]=t.x[1]=0; t.num--; } if(!vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]) { vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]=1; if(t.num==1 && !t.x[0]) { t.x[0]=t.x[1]; t.y[0]=t.y[1]; t.x[1]=0; } t.step++; que[bottom++]=t; } } else { if(t.x[1]-1>=1 && mp[t.x[1]-1][t.y[1]]!='*') t.x[1]--; for(i=0;i<2;i++) if(t.hx[i]==t.x[1] && t.hy[i]==t.y[1]) { t.hx[i]=t.x[1]=0; t.num--; } if(t.x[0]-1>=1 &&mp[t.x[0]-1][t.y[0]]!='*' && !(t.x[1]==t.x[0]-1 && t.y[1]==t.y[0])) t.x[0]--; for(i=0;i<2;i++) if(t.hx[i]==t.x[0] && t.hy[i]==t.y[0]) { t.hx[i]=t.x[0]=0; t.num--; } if(!vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]) { vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]=1; if(t.num==1 && !t.x[0]) { t.x[0]=t.x[1]; t.y[0]=t.y[1]; t.x[1]=0; } t.step++; que[bottom++]=t; } }//x-1 t=que[top]; if(t.x[0]>t.x[1])//x+1 { if(t.x[0]+1<=n && mp[t.x[0]+1][t.y[0]]!='*') t.x[0]++; for(i=0;i<2;i++) if(t.hx[i]==t.x[0] && t.hy[i]==t.y[0]) { t.hx[i]=t.x[0]=0; t.num--; } if(t.x[1]+1<=n && mp[t.x[1]+1][t.y[1]]!='*' && !(t.x[1]+1==t.x[0] && t.y[1]==t.y[0])) t.x[1]++; for(i=0;i<2;i++) if(t.hx[i]==t.x[1] && t.hy[i]==t.y[1]) { t.hx[i]=t.x[1]=0; t.num--; } if(!vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]) { vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]=1; if(t.num==1 && !t.x[0]) { t.x[0]=t.x[1]; t.y[0]=t.y[1]; t.x[1]=0; } t.step++; que[bottom++]=t; } } else { if(t.x[1]+1<=n && mp[t.x[1]+1][t.y[1]]!='*') t.x[1]++; for(i=0;i<2;i++) if(t.hx[i]==t.x[1] && t.hy[i]==t.y[1]) { t.hx[i]=t.x[1]=0; t.num--; } if(t.x[0]+1<=n &&mp[t.x[0]+1][t.y[0]]!='*' && !(t.x[1]==t.x[0]+1 && t.y[1]==t.y[0])) t.x[0]++; for(i=0;i<2;i++) if(t.hx[i]==t.x[0] && t.hy[i]==t.y[0]) { t.hx[i]=t.x[0]=0; t.num--; } if(!vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]) { vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]=1; if(t.num==1 && !t.x[0]) { t.x[0]=t.x[1]; t.y[0]=t.y[1]; t.x[1]=0; } t.step++; que[bottom++]=t; } }//x+1 t=que[top]; if(t.y[0]>t.y[1])//y+1 { if(t.y[0]+1<=m && mp[t.x[0]][t.y[0]+1]!='*') t.y[0]++; for(i=0;i<2;i++) if(t.hx[i]==t.x[0] && t.hy[i]==t.y[0]) { t.hx[i]=t.x[0]=0; t.num--; } if(t.y[1]+1<=m && mp[t.x[1]][t.y[1]+1]!='*' && !(t.x[1]==t.x[0] && t.y[1]+1==t.y[0])) t.y[1]++; for(i=0;i<2;i++) if(t.hx[i]==t.x[1] && t.hy[i]==t.y[1]) { t.hx[i]=t.x[1]=0; t.num--; } if(!vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]) { vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]=1; if(t.num==1 && !t.x[0]) { t.x[0]=t.x[1]; t.y[0]=t.y[1]; t.x[1]=0; } t.step++; que[bottom++]=t; } } else { if(t.y[1]+1<=m && mp[t.x[1]][t.y[1]+1]!='*') t.y[1]++; for(i=0;i<2;i++) if(t.hx[i]==t.x[1] && t.hy[i]==t.y[1]) { t.hx[i]=t.x[1]=0; t.num--; } if(t.y[0]+1<=m &&mp[t.x[0]][t.y[0]+1]!='*' && !(t.x[1]==t.x[0] && t.y[1]==t.y[0]+1)) t.y[0]++; for(i=0;i<2;i++) if(t.hx[i]==t.x[0] && t.hy[i]==t.y[0]) { t.hx[i]=t.x[0]=0; t.num--; } if(!vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]) { vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]=1; if(t.num==1 && !t.x[0]) { t.x[0]=t.x[1]; t.y[0]=t.y[1]; t.x[1]=0; } t.step++; que[bottom++]=t; } }//y+1 t=que[top]; if(t.y[0]
=1 && mp[t.x[0]][t.y[0]-1]!='*') t.y[0]--; for(i=0;i<2;i++) if(t.hx[i]==t.x[0] && t.hy[i]==t.y[0]) { t.hx[i]=t.x[0]=0; t.num--; } if(t.y[1]-1>=1 && mp[t.x[1]][t.y[1]-1]!='*' && !(t.x[1]==t.x[0] && t.y[1]-1==t.y[0])) t.y[1]--; for(i=0;i<2;i++) if(t.hx[i]==t.x[1] && t.hy[i]==t.y[1]) { t.hx[i]=t.x[1]=0; t.num--; } if(!vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]) { vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]=1; if(t.num==1 && !t.x[0]) { t.x[0]=t.x[1]; t.y[0]=t.y[1]; t.x[1]=0; } t.step++; que[bottom++]=t; } } else { if(t.y[1]-1>=1 && mp[t.x[1]][t.y[1]-1]!='*') t.y[1]--; for(i=0;i<2;i++) if(t.hx[i]==t.x[1] && t.hy[i]==t.y[1]) { t.hx[i]=t.x[1]=0; t.num--; } if(t.y[0]-1>=1 &&mp[t.x[0]][t.y[0]-1]!='*' && !(t.x[1]==t.x[0] && t.y[1]==t.y[0]-1)) t.y[0]--; for(i=0;i<2;i++) if(t.hx[i]==t.x[0] && t.hy[i]==t.y[0]) { t.hx[i]=t.x[0]=0; t.num--; } if(!vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]) { vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]=1; if(t.num==1 && !t.x[0]) { t.x[0]=t.x[1]; t.y[0]=t.y[1]; t.x[1]=0; } t.step++; que[bottom++]=t; } }//y-1 t=que[top]; } else//num==1 { if(t.x[0]+1<=n && mp[t.x[0]+1][t.y[0]]!='*') t.x[0]++; for(i=0;i<2;i++) if(t.hx[i]==t.x[0] && t.hy[i]==t.y[0]) { t.hx[i]=t.x[0]=0; t.num--; } if(!vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]) { vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]=1; t.step++; que[bottom++]=t; } t=que[top]; if(t.x[0]-1>=1 && mp[t.x[0]-1][t.y[0]]!='*') t.x[0]--; for(i=0;i<2;i++) if(t.hx[i]==t.x[0] && t.hy[i]==t.y[0]) { t.hx[i]=t.x[0]=0; t.num--; } if(!vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]) { vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]=1; t.step++; que[bottom++]=t; } t=que[top]; if(t.y[0]+1<=m && mp[t.x[0]][t.y[0]+1]!='*') t.y[0]++; for(i=0;i<2;i++) if(t.hx[i]==t.x[0] && t.hy[i]==t.y[0]) { t.hx[i]=t.x[0]=0; t.num--; } if(!vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]) { vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]=1; t.step++; que[bottom++]=t; } t=que[top]; if(t.y[0]-1>=1 && mp[t.x[0]][t.y[0]-1]!='*') t.y[0]--; for(i=0;i<2;i++) if(t.hx[i]==t.x[0] && t.hy[i]==t.y[0]) { t.hx[i]=t.x[0]=0; t.num--; } if(!vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]) { vis[t.x[0]][t.y[0]][t.x[1]][t.y[1]]=1; t.step++; que[bottom++]=t; } } top++; } if(top==bottom) printf("Sorry , sir , my poor program fails to get an answer.\n"); } }