Hdu1180 - 诡异的楼梯 - 广度优先搜索

#include<stdio.h>
#include<string.h>
int m,n;
char map[25][25],map1[25][25];
int mark[25][25];
int to[4][2]={{1,0},{-1,0},{0,1},{0,-1}};
struct
{
int x,y,id,stop/*0为不停，1为停*/;
}queue[1000],s,e,now,next;
int bfs()
{
memset(mark,0,sizeof(mark));
int fr,ed,i,j;
fr=ed=0;
s.stop=0;
s.id=0;
queue[ed++]=s;
mark[s.x][s.y]=1;
while(fr<ed)
{
now=queue[fr++];
if(now.id%2==0)
{
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
map1[i][j]=map[i][j];
}
}
}
else
{
for(i=0;i<m;i++)
{
for(j=0;j<n;j++)
{
if(map[i][j]=='|')
{
map1[i][j]='-';
}
else if(map[i][j]=='-')
{
map1[i][j]='|';
}
else
{
map1[i][j]=map[i][j];
}
}
}
}
if(now.x==e.x&&now.y==e.y&&now.stop!=1)
{
return now.id;
}
if(now.stop==1)
{
next.id=now.id+1;
next.x=now.x;
next.y=now.y;
next.stop=0;
queue[ed++]=next;
continue;
}
for(i=0;i<4;i++)
{
next.x=now.x+to[i][0];
next.y=now.y+to[i][1];
if(i<2&&map1[next.x][next.y]=='-')
{
next.stop=1;
}
else if(i>=2&&map1[next.x][next.y]=='|')
{
next.stop=1;
}
else
{
next.stop=0;
}
if(map1[next.x][next.y]=='-'||map1[next.x][next.y]=='|')
{
next.x+=to[i][0];
next.y+=to[i][1];
}
if(next.x<0||next.y<0||next.x>=m||next.y>=n||mark[next.x][next.y]==1||map1[next.x][next.y]=='*')
{
continue;
}
next.id=now.id+1;
mark[next.x][next.y]=1;
queue[ed++]=next;
}
}
}
int main()
{
int i,j;
while(scanf("%d%d",&m,&n)!=EOF)
{
for(i=0;i<m;i++)
{
getchar();
for(j=0;j<n;j++)
{
scanf("%c",&map[i][j]);
if(map[i][j]=='S')
{
s.x=i;
s.y=j;
}
if(map[i][j]=='T')
{
e.x=i;
e.y=j;
}
}
}
printf("%d\n",bfs());
}
}