POJ 2935 Basic Wall Maze BFS

注意墙的处理，我是这么做的，把每个方块不能行走的方向标记出来，剩他的就是传统BFS了。

#include<stdio.h>#include<queue>using namespace std;int sx,sy,ex,ey;int h[4]={1,-1,0,0};int g[4]={0,0,1,-1};int dir[8][8][5];bool visit[7][7];struct point{int x;int y;int time;int pre;char dir;}que[1000];void limdir(int a,int b,int c,int d){int i;if(a==c){for(i=b+1;i<=d;i++){dir[c][i][0]=1;dir[c+1][i][1]=1;}}else if(b==d){for(i=a+1;i<=c;i++){dir[i][b][2]=1;dir[i][b+1][3]=1;}}}char cal(int i){if(i==0)return 'S';else if(i==1)return 'N';else if(i==2)return 'E';elsereturn 'W';}void print(int tem){if(que[tem].pre!=-1){print(que[tem].pre);printf("%c",que[tem].dir);}}int bfs(){int front=0,rear=0,xx,yy,i,j,k;struct point cur;cur.x=sx;cur.y=sy;cur.time=0;cur.pre=-1;que[rear++]=cur;while(front<rear){struct point tem;tem=que[front];for(i=0;i<4;i++){xx=tem.x+h[i];yy=tem.y+g[i];if(xx<=0 || xx>6 || yy<=0 || yy>6)continue;if(dir[tem.x][tem.y][i])continue;if(visit[xx][yy])continue;struct point pp;pp.x=xx;pp.y=yy;pp.time=tem.time+1;pp.pre=front;pp.dir=cal(i);que[rear]=pp;visit[xx][yy]=1;if(xx==ex && yy==ey){print(rear);printf("\n");return 1;}rear++;}front++;}return 0;}int main(){int i,j,k,a,b,c,d;while(scanf("%d %d",&sy,&sx) && !(sx==0 && sy==0)){scanf("%d %d",&ey,&ex);memset(dir,0,sizeof(dir));memset(visit,0,sizeof(visit));for(i=1;i<=3;i++){scanf("%d %d %d %d",&b,&a,&d,&c);limdir(a,b,c,d);}visit[sx][sy]=1;bfs();}}