1 #include<stdio.h>
2 #include<string.h>
3 #include<set>
4 #include<time.h>
5 using namespace std;
6
7 typedef int state[9];
8 const int max=1000000;
9 state st[max],goal;
10 int dist[max];
11 const int dx[]={-1,1,0,0};
12 const int dy[]={0,0,-1,1};
13
14 struct cmp
15 {
16 bool operator ()(int a,int b)const
17 {
18 return memcmp(&st[a],&st[b],sizeof(st[b]))<0;
19 }
20 };
21
22 set<int, cmp> vis;
23
24 void in()
25 {
26 vis.clear();
27 }
28
29 int insert(int s)
30 {
31 if(vis.count(s)) return 0;
32 vis.insert(s);
33 return 1;
34 }
35
36 int bfs()
37 {
38 int front,rear,z,d,newy,newz,newx,x,y;
39 rear=2;
40 front=1;
41 //state s,t;
42 in();
43 while(front<rear)
44 {
45 state &s=st[front];
46 if(memcmp(goal,s,sizeof(s))==0) return front;
47 for(z=0;z<9;z++) if(!s[z]) break;
48 x=z/3;y=z%3;
49 for(d=0;d<4;d++)
50 {
51 newx=x+dx[d];
52 newy=y+dy[d];
53 newz=newx*3+newy;
54 if(newx>=0&&newx<3&&newy>=0&&newy<3)
55 {
56 state &t=st[rear];
57 memcpy(&t,&s,sizeof(s));
58 t[newz]=s[z];
59 t[z]=s[newz];
60 dist[rear]=dist[front]+1;
61 if(insert(rear)) rear++;
62 }
63 }
64 front++;
65 }
66 return 0;
67 }
68
69 int main()
70 {
71 int i,ans;
72 for(i=0;i<9;i++) scanf("%d",&st[1][i]);
73 for(i=0;i<9;i++) scanf("%d",&goal[i]);
74 ans=bfs();
75 if(ans>0) printf("%d\n",dist[ans]);
76 else printf("-1\n");
77 printf("%d\n",clock()/CLOCKS_PER_SEC);
78 return 0;
79 }
