迷宫问题：hdoj1242--BFS基本应用

#include <iostream>using namespace std;const int MAX=205;char map[MAX][MAX];int bfs_search(int si,int sj,int di,int dj){int dir[4][2]={0,1,0,-1,1,0,-1,0};int newi,newj;typedef struct {int i,j,lev;int guard;}Queue;Queue Q[MAX*MAX];Queue e;int top,rear;top=rear=0;Q[rear].i=si;Q[rear].j=sj;Q[rear].guard=0;Q[rear].lev=0;rear++;while(top!=rear){e=Q[top++];if(e.i==di && e.j==dj)return e.lev;if(e.guard==1){e.guard=0;e.lev++;Q[rear++]=e;}else{for(int k=0;k<4;k++){newi=e.i+dir[k][0];newj=e.j+dir[k][1];if(map[newi][newj]!='#'){Q[rear].i=newi;Q[rear].j=newj;Q[rear].lev=e.lev+1;if(map[newi][newj]=='x')Q[rear].guard=1;elseQ[rear].guard=0;map[newi][newj]='#';rear++;}}}}return 0;}void main(){int N,M;int si,sj,di,dj;while(scanf("%d%d",&N,&M)!=EOF){int i,j;for(i=0;i<=N+1;i++)map[i][0]=map[i][M+1]='#';for(j=1;j<=M;j++)map[0][j]=map[N+1][j]='#';for(i=1;i<=N;i++){for(j=1;j<=M;j++){cin>>map[i][j];if(map[i][j]=='a'){si=i;sj=j;}else if(map[i][j]=='r'){di=i;dj=j;}}}int nstep=bfs_search(si,sj,di,dj);if(nstep!=0)cout<<nstep<<endl;elsecout<<"Poor ANGEL has to stay in the prison all his life."<<endl;}}