八数码

2 6 4 1 3 7 0 5 8
8 1 5 7 3 6 4 0 2
31
treap sbt splay
//今天写的八数码 速度不行呀、老超时、照着白皮书写的
#include <iostream>
#include <stdio.h>
#include <string.h>
#include <algorithm>
#include <queue>
#define MAXSIZE 362888
using namespace std;
typedef int State[9];
State st[MAXSIZE],goal;
int dis[MAXSIZE];
bool hash[MAXSIZE];
int dir[4][2]={0,1,0,-1,1,0,-1,0};
int fac[9],f[MAXSIZE];
bool can_in(State &yy)
{
    int c=0,k;
    for(int i=0;i<9;i++)
      {    k=0;
          for(int j=i+1;j<9;j++)
             if(yy[j]<yy[i])
               k++;
          c+=k*fac[8-i];
      }
    if(hash[c])
     return 0;
    hash[c]=1;
    return 1;
}
int BFS()
{
    int i;
    int z,newz,x,y,newx,newy;
    int first=1,back=2;
    State t;
    while(first<back)
    {
        State &s=st[first];
        if(memcmp(&s,&goal,sizeof(s))==0) return first;
        for(z=0;z<9;z++) if(s[z]==0) break;
        x=z/3; y=z%3;
        for(i=0;i<4;i++)
        {
            newx=x+dir[i][0];
            newy=y+dir[i][1];
            if(newx>=0&&newx<3&&newy>=0&&newy<3)
            {
                newz=newx*3+newy;
                State &t=st[back];
                memcpy(&t,&s,sizeof(t));
                t[newz]=s[z];
                t[z]=s[newz];
                if(can_in(t))
                {
                     dis[back]=dis[first]+1;
                     f[back]=first;
                     back++;
                }
            }
        }
        first++;
    }
    return 0;
}
char rc[MAXSIZE];
int main()
{
    int i;fac[0]=1;
    for(i=1;i<9;i++)
     fac[i]=fac[i-1]*i;
    for(i=0;i<9;i++) goal[i]=(i+1)%9;
     f[1]=1;
    int hs[133];hs['x']=hs['X']=0;
    for(i='1';i<='8';i++)
     hs[i]=i-'0';
     char c;
    while(scanf("%c",&c)!=EOF)
    {
        st[1][0]=hs[c];i=1;
        while(scanf("%c",&c),c!='\n')
        {
           if(c!=' ') st[1][i++]=hs[c];
        }
        memset(hash,0,sizeof(hash));
        int fa,s=BFS();
           i=0;
        int zs,zf;
        while(f[s]!=s)
        {
            fa=f[s];
            for(zs=0;zs<9;zs++) if(st[s][zs]==0) break;
            for(zf=0;zf<9;zf++) if(st[fa][zf]==0) break;
            if(zf<zs)
            {
               if(zs-zf==1)
                rc[i++]='r';
               else
                rc[i++]='d';
            }
            else
            {
                if(zf-zs==1)
                rc[i++]='l';
               else
                rc[i++]='u';
            }
            s=fa;
        }
       for(s=i-1;s>=0;s--)
        printf("%c",rc[s]);
       printf("\n");
    }
    return 0;
}