2048小游戏后端的实现

游戏的由来

2048小游戏是首先在github上发布的一款开源的小游戏, 游戏的规则十分简单, 但也意外的获得了世界上很多人的青睐。在这里, 我想介绍一下我实现2048小游戏后端的一些小算法的设计。

A.栈的使用

在2048的游戏当中, 最主要的操作便是上下左右的操作, 而这里, 我们需要使用一个常用的数据结构--栈。在移动方块的时候, 相同数字的方块会在移动的过程中融合。这和栈只允许栈顶作操作的特点十分吻合。所以, 首先需要实现的是一个栈(当然大部分语言的标准库内都有这样的内容, 详情看下面的代码)

B.新方块的产生

在2048当中, 在每一次的移动之后后端需要做两项操作, 首先是判断游戏是否可以通过移动来产生方块的融合, 其次则是找到一个任意的空位来产生一个新的方块。
首先是判断游戏是否结束。在这里我们可以采用BFS的方法, 对每个方块进行尽量的广度搜索, 从而找到可以融合的地方。其次是找到一个任意的空位。我们将空位的x,y坐标都用线性表储存起来, 然后对这个线性表执行一次洗牌操作, 就可以任意找到一个空白的位置来插入一个新的方块了, 这样大致2048游戏的后端就完成了。

下面是实现的代码:

首先是线性栈, 因为无聊所以写了一个:

#the stack module is designed for the movement of
#puzzle.

class Stack:
def __init__(self):
#the base is the element list
self.__base =[]
#the number of the element in the stack
self.length =0
#the top points to the top element of the stack
self.__top =0

#the insert function is for element insertion
def insert(self, n):
self.__base.append(n)
self.length +=1
self.__top  +=1
#change the lenght and the top pointers

#to pop the head element in the stack
def pop(self):
if self.__top >0:
self.__base.pop(self.__top-1)
self.length -=1
self.__top -=1

#return the head element in the stack
def front(self):
if(self.__top >0):
return self.__base[self.__top-1]
else: return 0

下面是主要操作的实现:

import random
from stack import *

class puzzle:
#create the puzzle of the game of a given size
def __init__(self, n):
self.__board =[]
for i in range(n):
self.__board.append(n*[0])

self.__size =n
#set the initial size and board

#find a proper position to insert the element
def creatInsertLocation(self):
#use a list to decide the location of insertion
stack =[]
for i in range(self.__size):
for j in range(self.__size):
if(self.__board[i][j]==0):stack.append([i,j])

#decide which number to insert
x =random.randint(1,2)
if(len(stack)>0):
random.shuffle(stack)
z =stack[0][0]
y =stack[0][1]
self.__board[z][y] =2**x
return True
else:
return False

#This function aims to print the whole board
def showBoard(self):
print self.__board

#this method is designed for judge the game can go on
def moveable(self):
flag =False   #to record if the puzzle is moveable
mvx =[1,-1,0,0]
mvy =[0,0,1,-1]
for i in range(self.__size):
for j in range(self.__size):
for k in range(4):
mx =i+mvx[k]
my =j+mvy[k]
#if the index is out of range, then continue
if(mx<0 or mx>=self.__size or my <0 or my >=self.__size):
continue
#if we find a movable position, then the whole puzzle is movable
if(self.__board[i][j] ==self.__board[mx][my]):
flag =True
break
if(flag):break;
if(flag):break;
return flag

#this function defines the up move
def upMove(self):
for i in range(self.__size):
s =Stack()
for j in range(self.__size):
if(self.__board[j][i] ==0):continue
elif self.__board[j][i] ==s.front():
s.pop()
s.insert(2*self.__board[j][i])
elif self.__board[j][i] !=s.front():
s.insert(self.__board[j][i])
self.__board[j][i] =0
for j in range(s.length-1, -1, -1):
self.__board[j][i] =s.front()
s.pop()

#this function is designed for the puzzle down move
def downMove(self):

for i in range(self.__size):
s =Stack()
for j in range(self.__size -1, -1, -1):
if(self.__board[j][i] ==0):continue
elif self.__board[j][i] ==s.front():
s.pop()
s.insert(2*self.__board[j][i])
elif self.__board[j][i] !=s.front():
s.insert(self.__board[j][i])
self.__board[j][i] =0
for j in range(s.length, 0, -1):
self.__board[self.__size -j][i] =s.front()
s.pop()

#this function is designed for the left move of the puzzle
def leftMove(self):
for i in range(self.__size):
s =Stack()
for j in range(self.__size):
if(self.__board[i][j] ==0):continue
elif self.__board[i][j] ==s.front():
s.pop()
s.insert(2*self.__board[i][j])
elif self.__board[i][j] !=s.front():
s.insert(self.__board[i][j])
self.__board[i][j] =0
for j in range(s.length -1, -1, -1):
self.__board[i][j] =s.front()
s.pop()

#this function is designed for the right move of the puzzle
def rightMove(self):
for i in range(self.__size):
s =Stack()
for j in range(self.__size-1, -1, -1):
if(self.__board[i][j] ==0):continue
elif self.__board[i][j] ==s.front():
s.pop()
s.insert(2*self.__board[i][j])
elif self.__board[i][j] !=s.front():
s.insert(self.__board[i][j])
self.__board[i][j] =0
for j in range(s.length, 0, -1):
self.__board[i][self.__size -j] =s.front()
s.pop()

def getElem(self,i, j):
return self.__board[i][j]

结语

十分遗憾的是, 由于本人的前端设计实在太渣, 所以没有实现相应的前端。在此如果有实现前端设计的同道中人欢迎将代码发送到我的邮箱wyc8094@gmail.com 谢谢！！