Simple UVA 11624 fire! , BFS.

Description

Joe works in a maze. Unfortunately, portions of the maze has caught on fire, and the owner of the maze neglected to create a fire escape plan. Help Joe escape the maze.

Given Joe's location in the maze and which squares of the maze is on fire, you must determine whether Joe can exit the MA Ze before the fire reaches him, and what fast he can do it.

Joe and the fire all move one square per minute, vertically or horizontally (not diagonally). The fire spreads all four directions from each square, that's on fire. Joe may exit the maze from any square that borders the edge of the maze. Neither Joe nor the fire could enter a square that's occupied by a wall.

The question is the maze problem, and then added the fire, but this problem is a pit, the original fire is not just one, can have a lot of ...

This problem first from the fire BFS again, so that you can know how long after the fire burned to a piece, and then from the person BFS, when the fire has been burned over the words even if they can not pass the good.

The code is as follows:

#include <iostream>#include<cstdio>#include<cstring>#include<queue>#include<cmath>using namespacestd;BOOLmap1[1005][1005];intrem[1005][1005];intfrem[1005][1005];intn,m;intsi,sj,fi[1000006],fj[1000006];intcou;BOOLJudgeintXintYinttemp) {    if(x<=0|| y<=0|| x>n| | Y>M)return 0; if(!Map1[x][y])return 0; if(Rem[x][y])return 0; if(frem[x][y]>-1&&temp>=Frem[x][y])return 0; return 1;}BOOLJudge1 (intXinty) {    if(x<=0|| y<=0|| x>n| | Y>M)return 0; if(!Map1[x][y])return 0; if(frem[x][y]!=-1)        return 0; return 1;}intSlove () {Queue<int>que; inttemp,t1,t2; Que.push (Si*1010+Sj); REM[SI][SJ]=1;  while(!Que.empty ()) {Temp=Que.front ();        Que.pop (); T1=temp/1010; T2=temp%1010; Temp=REM[T1][T2]; if(t1==1|| t2==1|| t1==n| | t2==M)returntemp; --T1; if(judge (t1,t2,temp)) {Que.push (T1*1010+T2); REM[T1][T2]=temp+1; } T1+=2; if(judge (t1,t2,temp)) {Que.push (T1*1010+T2); REM[T1][T2]=temp+1; }        --T1; --T2; if(judge (t1,t2,temp)) {Que.push (T1*1010+T2); REM[T1][T2]=temp+1; } T2+=2; if(judge (t1,t2,temp)) {Que.push (T1*1010+T2); REM[T1][T2]=temp+1; }    }    return-1;}voidinit () {Queue<int>que; inttemp,t1,t2;  for(intI=0; i<cou;++i) {Que.push (Fi[i]*1010+Fj[i]); Frem[fi[i]][fj[i]]=0; }     while(!Que.empty ()) {Temp=Que.front ();        Que.pop (); T1=temp/1010; T2=temp%1010; Temp=FREM[T1][T2]; --T1; if(Judge1 (t1,t2)) {Que.push (T1*1010+T2); FREM[T1][T2]=temp+1; } T1+=2; if(Judge1 (t1,t2)) {Que.push (T1*1010+T2); FREM[T1][T2]=temp+1; }        --T1; --T2; if(Judge1 (t1,t2)) {Que.push (T1*1010+T2); FREM[T1][T2]=temp+1; } T2+=2; if(Judge1 (t1,t2)) {Que.push (T1*1010+T2); FREM[T1][T2]=temp+1; }    }}intMain () {Ios::sync_with_stdio (false); intT; intans; CharC; CIN>>u;  while(t--) {cou=0; CIN>>N>>M;  for(intI=1; i<=n;++i) for(intj=1; j<=m;++j) {Rem[i][j]=0; FREM[I][J]=-1; CIN>>C; if(c=='#'|| c=='F') Map1[i][j]=0; ElseMap1[i][j]=1; if(c=='J') Si=i,sj=J; if(c=='F') {Fi[cou]=i; Fj[cou++]=J;        }} init (); Ans=Slove (); if(ans==-1) cout<<"impossible\n"; Elsecout<<ans<<Endl; }    return 0;}

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Simple UVA 11624 fire! , BFS.