[hdu 1067]bfs+hash

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1067

queue里面果然不能放vector，还是自己写的struct比较省内存……

#include<bits/stdc++.h>
using namespace std;

int a[4][8];
const int INF=0x3f3f3f3f;
const int p=55566677;
const int md=1000000007;

struct Node
{
    int a[4][8];
    Node(){}
    Node(const int x[4][8])
    {
        for (int i=0;i<4;i++)
            for (int j=0;j<8;j++)
                a[i][j]=x[i][j];
    }
    int gethash() const
    {
        int now=0;
        for (int i=0;i<4;i++)
            for (int j=0;j<8;j++)
                now=(1ll*now*p%md+a[i][j])%md;
        return now;
    }
};


const int End[4][8]=
{
    {11,12,13,14,15,16,17,0},
    {21,22,23,24,25,26,27,0},
    {31,32,33,34,35,36,37,0},
    {41,42,43,44,45,46,47,0}
};

const Node endNode(End);

const int term=endNode.gethash();

unordered_map<int,int> M;

queue<Node> q;

int bfs()
{
    M.clear();
    while (!q.empty()) q.pop();
    for (int i=0;i<4;i++)
        for (int j=1;j<8;j++)
            if (a[i][j]%10==1)
            {
                int tmp=a[i][j];
                a[i][j]=0;
                a[tmp/10-1][0]=tmp;
            }
    Node tmp;
    for (int i=0;i<4;i++) for (int j=0;j<8;j++) tmp.a[i][j]=a[i][j];
    q.push(tmp);
    int H=tmp.gethash();
    if (H==term) return 0;
    M[H]=0;
    while (!q.empty())
    {
        Node now=q.front();
        int st=M[now.gethash()];
        q.pop();
        for (int i=0;i<4;i++)
            for (int j=1;j<8;j++)
                if (now.a[i][j]==0 && now.a[i][j-1]%10!=7)
                {
                    int tar=now.a[i][j-1]+1;
                    int K=-1;
                    for (int I=0;I<4;I++)
                    {
                        for (int J=1;J<8;J++)
                        {
                            if (now.a[I][J]==tar)
                            {
                                K=I*8+J;
                                break;
                            }
                        }
                        if (K!=-1) break;
                    }
                    now.a[i][j]=tar;
                    now.a[K/8][K%8]=0;
                    int H=now.gethash();
                    if (!M.count(H))
                    {
                        if (H==term) return st+1;
                        q.push(now);
                        M[H]=st+1;
                    }
                    now.a[i][j]=0;
                    now.a[K/8][K%8]=tar;
                }
    }
    return INF;
}

int main()
{
    int t;
    scanf("%d",&t);
    while (t--)
    {
        for (int i=0;i<4;i++)
            for (int j=1;j<8;j++)
                scanf("%d",&a[i][j]);
        int ans=bfs();
        if (ans!=INF) printf("%d
",ans);
        else printf("-1
");
    }
    return 0;
}