路径寻找问题……！

#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <cstdlib>
#include <stack>
#include <cctype>
#include <string>
#include <malloc.h>
#include <queue>
#include <map>

using namespace std;

const int INF = 0xffffff;
const double esp = 10e-8;
const double Pi = 4 * atan(1.0);
const int Maxn = 1000000;
const int mod = 10000007;
const int dr[] = {1,0,-1,0,-1,1,-1,1};
const int dc[] = {0,1,0,-1,1,-1,-1,1};

const int hashsize = 1000003;
int head[hashsize],next[Maxn];
typedef int State[9];
State st[Maxn],goal; //状态数组
int dist[Maxn];

void init_lookup_table(){
    memset(head,0,sizeof(head));
    memset(dist,0,sizeof(dist));
    memset(next,0,sizeof(next));
}
int hash(State & s){
    int v = 0;
    for(int i = 0;i < 9;i++){
        v += v * 10 + s[i];
    }
    return v % hashsize;
}

bool try_to_insert(int s){
    int h = hash(st[s]);
    int u = head[h];
    while(u){
        if(memcmp(&st[s],&st[u],sizeof(st[s])) == 0){
            return 0;
        }
        u = next[u];
    }
    next[s] = head[h];
    head[h] = s;
    return 1;
}

int bfs(){
    init_lookup_table();
    int front = 1;
    int rear = 2;
    while(front < rear){
        State &s = st[front];
        if(memcmp(s,goal,sizeof(s)) == 0)
            return front;
        int z;
        for(z = 0;z < 9;z++){
            if(!s[z])
                break;
        }
        int x = z/3;
        int y = z%3;
        for(int i = 0;i < 4;i++){
            int xx = x + dr[i];
            int yy = y + dc[i];
            int zz = xx * 3 + yy;
            if(xx >= 0 && xx < 3 && yy >= 0 && yy < 3){
                State &t = st[rear];
                memcpy(&t,&s,sizeof(s));
                t[zz] = s[z];
                t[z] = s[zz];
                dist[rear] = dist[front]+1;
                if(try_to_insert(rear) == 1){
                    rear++;
                   /* for(int j = 0;j < 9;j++){
                        if(j % 3 == 0)
                            cout << endl;
                        cout << t[j];
                    }
                    cout << endl;
                    if(rear == 70)
                        return -1;*/
                }
            }
        }
        front++;
    }
    return 0;
}

int main()
{
#ifndef ONLINE_JUDGE
    freopen("inpt.txt","r",stdin);
#endif
    for(int i = 0;i < 9;i++)
        scanf("%d",&st[1][i]);
    for(int i = 0;i < 9;i++)
        scanf("%d",&goal[i]);
    int ans = bfs();
    if(ans > 0)
        printf("%d\n",dist[ans]);
    else
        printf("-1\n");
    return 0;
}