The Morning after Halloween uva1601

这道题思路还是比较清晰的，建图加bfs或双向bfs，其实后者比前者少了将近一半的时间。。

建图可以把某一点所拥有邻接点长度（数目）记录在数组0这个位置，因为这道题使用vector会超时。

#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <vector>
#include <queue>
#include <map>
using namespace std;
char a[][];
int nex[][]= {,,,,-,,,-};
int book[][],top,book1[];
int w,h,n;
int sta[],ent[];
int mat[][];
inline bool is_inrage(int x,int y)
{
    if(x<||x>=h||y<||y>=w) return false;
    return true;
}
int findid(int x,int y)
{
    if(book[x][y]) return book[x][y];
    book[x][y]=++top;
    return book[x][y];
}
struct note
{
    int status[];
    int length;
    int step;
    note()
    {
        status[]=status[]=status[]=;
    }
};
short vis1[][][],vis2[][][];
bool invilid(int prea,int preb,int nowa,int nowb)
{
    if(nowa==nowb||(prea==nowb&&preb==nowa)) return true;
    return false;
}
int bfs(int len)
{
    memset(vis1,,sizeof(vis1));
    memset(vis2,,sizeof(vis2));
    queue<note>que1,que2;
    note start,ends;
    ends.length=start.length=len;
    ends.step=start.step=;
    for(int i=; i<len; i++)
    {
        start.status[i]=sta[i];
        ends.status[i]=ent[i];
    }
    que1.push(start);
    que2.push(ends);
    vis1[start.status[]][start.status[]][start.status[]]=;
    vis2[ends.status[]][ends.status[]][ends.status[]]=;
    int ac[],flag;
    struct note u1,v1,u2,v2;
    while(!que1.empty()||!que2.empty())
    {
        if(!que1.empty())
        {
            u1=que1.front();
            que1.pop();
            for(int i=; i<=mat[u1.status[]][]; i++)
            {
                ac[]=mat[u1.status[]][i];
                for(int j=; j<=mat[u1.status[]][]; j++)
                {
                    ac[]=mat[u1.status[]][j];
                    if(invilid(u1.status[],u1.status[],ac[],ac[])) continue;
                    for(int h=; h<=mat[u1.status[]][]; h++)
                    {
                        ac[]=mat[u1.status[]][h];
                        if(len==) if(invilid(u1.status[],u1.status[],ac[],ac[])) continue;
                        if(len==) if(invilid(u1.status[],u1.status[],ac[],ac[])) continue;
                        v1.step=u1.step+;
                        v1.length=u1.length;
                        v1.status[]=ac[];
                        v1.status[]=ac[];
                        v1.status[]=ac[];
                        if(vis1[v1.status[]][v1.status[]][v1.status[]]) continue;
                        vis1[v1.status[]][v1.status[]][v1.status[]]=v1.step;
                        que1.push(v1);
                        int a1,b1,c1;
                        a1=v1.status[];b1=v1.status[];c1=v1.status[];
                        if(vis2[a1][b1][c1]) return vis1[a1][b1][c1]+vis2[a1][b1][c1];
                    }
                }
            }
        }
        if(!que2.empty())
        {
            u2=que2.front();
            que2.pop();
            for(int i=; i<=mat[u2.status[]][]; i++)
            {
                ac[]=mat[u2.status[]][i];
                for(int j=; j<=mat[u2.status[]][]; j++)
                {
                    ac[]=mat[u2.status[]][j];
                    if(invilid(u2.status[],u2.status[],ac[],ac[])) continue;
                    for(int h=; h<=mat[u2.status[]][]; h++)
                    {
                        ac[]=mat[u2.status[]][h];
                        if(len==) if(invilid(u2.status[],u2.status[],ac[],ac[])) continue;
                        if(len==) if(invilid(u2.status[],u2.status[],ac[],ac[])) continue;
                        v2.step=u2.step+;
                        v2.length=u2.length;
                        v2.status[]=ac[];
                        v2.status[]=ac[];
                        v2.status[]=ac[];
                        if(vis2[v2.status[]][v2.status[]][v2.status[]]) continue;
                        vis2[v2.status[]][v2.status[]][v2.status[]]=v2.step;
                        que2.push(v2);
                        int a2,b2,c2;
                        a2=v2.status[];b2=v2.status[];c2=v2.status[];
                        if(vis1[a2][b2][c2]) return vis1[a2][b2][c2]+vis2[a2][b2][c2];
                    }
                }
            }
        }
    }
    return -;
}
struct node
{
    int x,y;
    char v;
    node() {}
    node(int xx,int yy,char vv):x(xx),y(yy),v(vv) {}
    bool operator < (const node &another) const
    {
        return v<another.v;
    }
};
int main()
{
    while(scanf("%d%d%d",&w,&h,&n),w+h+n)
    {
        char ch[];
        memset(book,,sizeof(book));
        node t1[],t2[];
        int s1=,s2=;
        memset(mat,,sizeof(mat));
        getchar();
        for(int i=; i<h; i++)
        {
            gets(ch);
            for(int j=; j<w; j++)
            {
                a[i][j]=ch[j];
                if('a'<=ch[j]&&ch[j]<='z')  t1[s1++]=node(i,j,ch[j]);
                if('A'<=ch[j]&&ch[j]<='Z')  t2[s2++]=node(i,j,ch[j]);
            }
        }
        int nx,ny,idpre,idnex;
        top=;
        for(int i=; i<h; i++)
        {
            for(int j=; j<w; j++)
            {
                for(int k=; k<; k++)
                {
                    if(a[i][j]=='#') continue;
                    nx=i+nex[k][];
                    ny=j+nex[k][];
                    if(is_inrage(nx,ny)&&a[nx][ny]!='#')
                    {
                        idpre=findid(i,j);
                        idnex=findid(nx,ny);
                        int lenth=++mat[idpre][];
                        mat[idpre][lenth]=idnex;
                    }
                }
            }
        }
        for(int i=; i<=top; i++)
        {
            ++mat[i][];
            mat[i][mat[i][]]=i;
        }
        sort(t1,t1+n);
        sort(t2,t2+n);
        for(int i=; i<n; i++)
        {
            sta[i]=findid(t1[i].x,t1[i].y);
            ent[i]=findid(t2[i].x,t2[i].y);
   //         cout<<sta[i]<<" "<<ent[i]<<endl;
        }
        printf("%d\n",bfs(n));
    }
    return ;
}