A*算法解决八数码问题

import copy
class node1:#定义的节点信息其中包括父亲节点信息，当前节点信息，步数
    def __init__(self,father,now,step):
       self.father=father
       self.now=now
       self.step=step

xx=[1,0,-1,0]#可以移动的四个方向
yy=[0,1,0,-1]
start=[[0, 0, 0], [0, 0, 0], [0, 0, 0]]#初始化初始状态
end=[[0, 0, 0], [0, 0, 0], [0, 0, 0]]#初始化目标状态
open=[]#初始化open、close
close=[]
def Isdangerous(x,y):#危险位置判断
    if x>=0 and x<=2 and y>=0 and y<=2:
        return 1
    return 0
    
def fin(temp):#最终状态判断
    for i in range(3):
        for j in range(3):
            if temp[i][j]!=end[i][j]:
                return 0
    return 1
    
def pd(temp1,temp2):#temp1和temp2状态是否相同
    for i in range(3):
        for j in range(3):
            if temp1[i][j]!=temp2[i][j]:
                return 0
    return 1

def cf(temp):#重复状态判断
    for item in open:
        if pd(item.now,temp)==1:
            return 1
    for item in close:
        if pd(item.now,temp)==1:
             return 1
    return 0

def gjhs(chess1,chess2):#估计函数进行判断这个状态与目标状态错位数字数量
    sum=0
    for i in range(3):
       for j in range(3):
           if  chess1[i][j]!=chess2[i][j]:
               sum+=1
    return sum

def BFS():#进行BFS遍历
    x=0
    y=0
    zt=[]
    while(len(open)!=0):
        zt = open[0].now
        bs=open[0].step
        if fin(zt)==1:
            return
        for i in range(3):
            for j in range(3):
                if zt[i][j]=='0':
                     x,y=i,j

        for i in range(4):
            nx=x+xx[i]
            ny=y+yy[i]
            if Isdangerous(nx,ny)==1:
                temp =copy.deepcopy(zt)#这里是深拷贝！！！
                arr=temp[x][y]
                temp[x][y]=temp[nx][ny]
                temp[nx][ny]=arr
                if cf(temp)==0:
                    temp2=node1(zt,temp,bs+1)
                    open.append(temp2)

        open.remove(open[0])#移除open表里面的第一个元素
        for i in range(len(open)):#按照估计函数值大小进行排序
            f1=gjhs(open[i].now,end)
            for j in range(i,len(open)):
                f2=gjhs(open[j].now,end)
                if f1>f2:
                    arr=open[i]
                    open[i]=open[j]
                    open[j]=arr
        close.append(open[0])#添加到close列表里面

def printf(chess):#用来输出测试
    for i in range(3):
        for j in range(3):
            print(chess[i][j],end=' ')
        print()

def nixushu(chess):#逆序数计算
    list=[]
    sum=0
    for i in range(3):
        for j in range(3):
            list.append(chess[i][j])
    for i in range(1,len(list)):
      if list[i]!='0':
        for j in range(0,i):
            if list[j]>list[i]:
                sum+=1
    return sum

def jo(num):#奇数偶数判断
    if num%2==0:
        return 1
    return 0

if __name__ == "__main__":#主函数

    print("请输入初始状态:")
    for i in range(3):
        line=input().split(' ')
        for j in range(3):
            start[i][j]=line[j]
    open.append(node1([],start,0))
    print("请输入目标状态:")
    for i in range(3):
        line1=input().split(' ')
        for j in range(3):
            end[i][j]=line1[j]
    if jo(nixushu(start))==jo(nixushu(end)):
        BFS()
        lj=[]
        lj.append(close[-1].now)
        father=close[-1].father
        while True:
            if pd(father,start)==1:
                lj.append(father)
                break
            else:
                for item in close:
                    if pd(father,item.now)==1:
                        lj.append(father)
                        father=item.father
        sum=0
        print("找到的解路径")
        for i in range(-1,-len(lj)-1,-1):
            print("第%d步:"%sum)
            printf(lj[i])
            print()
            sum+=1
    else:
        print("找不到一个路径！")