Poj 1077 Eight！（BFS）

吃完晚饭，啃着tomato来poj上提交，结果不支持unordered_map，吐血啦，看来还是要用BFS+康托展开，还想再写一篇双向BFS的，对这道题算是圆满了*_*，但是要用G++提交，C++会报错我也不知道为嘛

#include<iostream> 
#include<cstring>
#include<queue>
using namespace std;
const int N=362880;
struct node{
    int count,state[9];
    char op[100];
};
int vis[N],start[9];
int goal[9]={1,2,3,4,5,6,7,8,0};
int dir[4][2]={{1,0},{-1,0},{0,-1},{0,1}};//rlud
long int factory[]={1,1,2,6,24,120,720,5040,40320,362880};
bool Cantor(int str[],int n){
    long ans=0;
    for(int i=0;i<n;i++){
        int cnt=0;
        for(int j=i+1;j<n;j++){
            if(str[i]>str[j]) ++cnt;
        }
        ans+=cnt*factory[n-i-1];
    }
    if(!vis[ans]){
        vis[ans]=1;
        return 1;
    }else{
        return 0;
    }
}
int BFS(){
    memset(vis,0,sizeof(vis));
    node head;
    queue<node> q;
    head.count=0;
    memcpy(head.state,start,sizeof(head.state));
    q.push(head);
    while(!q.empty()){
        head=q.front();
        q.pop();
        if(memcmp(head.state,goal,sizeof(goal))==0){
            for(int i=0;i<head.count;i++) cout<<head.op[i];
            return 1;
        }
        int z;
        for(z=0;z<9;z++){
            if(head.state[z]==0) break;
        }
        int x=z%3;
        int y=z/3;
        for(int i=0;i<4;i++){
            int dx=x+dir[i][0];
            int dy=y+dir[i][1];
            int dz=dx+3*dy;
            if(dx>=0&&dx<3&&dy>=0&&dy<3){
                node tmp;
                memcpy(&tmp,&head,sizeof(struct node));
                swap(tmp.state[z],tmp.state[dz]);
                if(i==0){//rlud
                    tmp.op[tmp.count]='r';
                    tmp.count++;
                }else if(i==1){
                    tmp.op[tmp.count]='l';
                    tmp.count++;
                }else if(i==2){
                    tmp.op[tmp.count]='u';
                    tmp.count++;
                }else if(i==3){
                    tmp.op[tmp.count]='d';
                    tmp.count++;
                }
                if(Cantor(tmp.state,9)) q.push(tmp);
            }
        }
    }
    return -1;    
}
signed main(){
    ios::sync_with_stdio(false);
    cin.tie(0);cout.tie(0);
    char ch;
    for(int i=0;i<9;i++){
        cin>>ch;
        if(ch=='x') start[i]=0;
        else start[i]=ch-'0';
    }
    int ans=BFS();
    if(ans==-1) cout<<"unsolvable"<<endl;
    
    return 0;
}