时钟【BFS】

#include <cstdio>
#include <iostream>
#include <map>
using namespace std;

const int d[][10]={{},{1,2,4,5},{1,2,3},{2,3,5,6},{1,4,7},{2,4,5,6,8},{3,6,9},{4,5,7,8},{7,8,9},{5,6,8,9}};  //变换情况
const int num[]={0,4,3,4,3,5,3,4,3,4};  //每种情况变换时钟的个数

int head,tail,state[300001][10],father[300001],z[300001];
bool p[5][5][5][5][5][5][5][5][5];  //判重专用

bool inmap(int y)  //判重
{
    if (p[state[y][1]][state[y][2]][state[y][3]][state[y][4]][state[y][5]][state[y][6]][state[y][7]][state[y][8]][state[y][9]])
     return true;
    p[state[y][1]][state[y][2]][state[y][3]][state[y][4]][state[y][5]][state[y][6]][state[y][7]][state[y][8]][state[y][9]]=1;
    return false;
}

void find(int x)  //递归输出路径
{
    if (father[x]!=0) find(father[x]);
    printf("%d ",z[x]);
    return;
}

bool check(int x)  //判断是否达成目标
{
    for (int i=1;i<=9;i++)
     if (state[x][i]!=4) return false;
    return true;
}

void bfs()
{
    do
    {
        head++;
        for (int i=1;i<=9;i++)
        {
            tail++;
            for (int j=1;j<=9;j++)
             state[tail][j]=state[head][j];  
            for (int j=0;j<num[i];j++)
             state[tail][d[i][j]]=state[head][d[i][j]]%4+1;  //变换
            if (inmap(tail))   //已经出现过
            {
                tail--;
                continue;
            }
            z[tail]=i;  //记录变换方式
            father[tail]=head;
            if (check(tail))  //达成目标
            {
                find(tail);
                return;
            }
        }
    }
    while (head<tail);
}

int main()
{
    head=-1;
    tail=0;
    for (int i=1;i<=3;i++)
     for (int j=1;j<=3;j++)
     {
        scanf("%d",&state[0][i*3-3+j]);
        state[0][i*3-3+j]/=3;  //离散
     }
    inmap(0);  
    bfs();
    return 0;
}