胜利大逃亡(续)

4 5 17
@A.B.
a*.*.
*..*^
c..b*

4 5 16
@A.B.
a*.*.
*..*^
c..b*

16
-1

<h3>#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
#include<queue>
using namespace std;
const int maxn=20+10;
char map[maxn][maxn];
int n,m,t;
bool vis[maxn][maxn][(1<<10)+10];
int dx[]={-1,1,0,0};
int dy[]={0,0,-1,1};
struct Point
{
    int x,y,step;
    int key;
};
queue<Point>Q;
Point st;
bool check(int x,int y)
{
    if(x>=1&&x<=n&&y>=1&&y<=m&&map[x][y]!='*')
         return true;
    return false;
}
int bfs()
{
    while(!Q.empty())  Q.pop();
    memset(vis,false,sizeof(vis));
    vis[st.x][st.y][st.key]=true;
    st.key=st.step=0;
    Q.push(st);
    Point cur,nex;
    while(!Q.empty())
    {
        cur=Q.front();
        Q.pop();
        if(map[cur.x][cur.y]=='^')
            return cur.step;
        for(int i=0;i<4;i++)
        {
            nex.x=cur.x+dx[i];
            nex.y=cur.y+dy[i];
            nex.key=cur.key;
            if(check(nex.x,nex.y))
            {
               nex.step=cur.step+1;
               if(nex.step>=t)
                   continue;
               else if(map[nex.x][nex.y]>='A'&&map[nex.x][nex.y]<='Z')
               {
                  int temp=map[nex.x][nex.y]-'A';
                  int nk=cur.key&1<<temp;
                  if(nk&&!vis[nex.x][nex.y][nex.key])
                  {
                      vis[nex.x][nex.y][nex.key]=true;
                      Q.push(nex);
                  }
               }
               else if(map[nex.x][nex.y]>='a'&&map[nex.x][nex.y]<='z')
               {
                   int temp=map[nex.x][nex.y]-'a';
                   nex.key=cur.key|1<<temp;
                   if(!vis[nex.x][nex.y][nex.key])
                   {
                       vis[nex.x][nex.y][nex.key]=true;
                       Q.push(nex);
                   }
               }
               else
               {
                   if(!vis[nex.x][nex.y][nex.key])
                   {
                       vis[nex.x][nex.y][nex.key]=true;
                       Q.push(nex);
                   }
               }
            }
         }
    }
    return -1;
}
inline void read_graph()
{
    char str[maxn];
    for(int i=1;i<=n;i++)
    {
        scanf("%s",str+1);
        for(int j=1;j<=m;j++)
        {
            if(str[j]=='@')
            {
                st.x=i;
                st.y=j;
                map[i][j]=str[j];
            }
            else  map[i][j]=str[j];
        }
}
int main()
{
    while(~scanf("%d%d%d",&n,&m,&t))
    {
        read_graph();
        int ans=bfs();
        printf("%d\n",ans);
    }
    return 0;
}</h3><h4><h3>    }</h3></h4>