Python宝典第五章：数据结构与算法

来源：互联网发布：java getclassname 编辑：程序博客网时间：2024/06/12 10:12

表：列表来创建

栈：

<span style="font-size:14px;"># -*- coding:utf-8 -*-# file: pystack.py#class PyStack:    def __init__(self, size = 20):        self.stack=[]        self.size=size        self.top=-1    def setSize(self, size):        self.size=size    def push(self, element):        if self.isFull():            raise StackException("PyStackOverFlow")        else:            self.stack.append(element)            self.top=self.top+1    def pop(self):        if self.isEmpty():            raise StackException("PyStackUnderFlow")        else:            element = self.stack[-1]            self.top=self.top-1            del self.stack[-1]            return element    def Top(self):        return self.top    def empty(self):        self.stack=[]        self.top=-1    def isEmpty(self):        if self.top==-1:            return True        else:            return False    def isFull(self):        if self.top==self.size-1:            return True        else:            return Falseclass StackException(Exception):    def __init__(self,data):        self.data=data    def __str__(self):        return self.dataif __name__=="__main__":    stack=PyStack()    for i in range(10):        stack.push(i)    print(stack.Top())    for i in range(10):        print(stack.pop())    stack.empty()</span>

队列：

# -*- coding:utf-8 -*-# file: pyqueue.py#class PyQueue:    def __init__(self,size=20):        self.queue=[]        self.size=size        self.end=-1    def setSize(self, size):        self.size=size    def In(self, element):        if self.end<self.size-1:            self.queue.append(element)            self.end=self.end+1        else:            raise QueueException("PyQueueFull")    def Out(self):        if self.end !=-1:            element=self.queue[0]            self.queue=self.queue[1:]            self.end=self.end-1            return element        else:            raise QueueException("PyQueueEmpty")    def End(self):        return self.end    def empty(self):        self.queue=[]        self.end=-1class QueueException(Exception):    def __init__(self,data):        self.data=data    def __str__(self):        return self. dataif __name__=="__main__":    queue=PyQueue()    for i in range(10):        queue.In(i)        #print(i)    print(queue.End())    for i in range(10):        #queue.Out();        print(queue.Out())    for i in range(20):        queue.In(i)    queue.empty()

二叉树：

# -*- coding:utf-8 -*-# file: pybtree.py#class BTree:    def __init__(self, value):        self.left=None        self.data=value        self.right=None    def insertLeft(self, value):        self.left=BTree(value)        return self.left    def insertRight(self, value):        self.right=BTree(value)        return self.right    def show(self):        print(self.data)def preorder(node):    if node.data:        node.show()        if node.left:            preorder(node.left)        if node.right:            preorder(node.right)def inorder(node):    if node.data:                if node.left:            inorder(node.left)        node.show()        if node.right:            inorder(node.right)def postorder(node):    if node.data:                if node.left:            postorder(node.left)        if node.right:            postorder(node.right)        node.show()if __name__=="__main__":    Root=BTree("Root")    A=Root.insertLeft("A")    C=A.insertLeft("C")    D=A.insertRight("D")    F=D.insertLeft("F")    G=D.insertRight("G")    B=Root.insertRight("B")    E=B.insertRight("E")    print("***********************")    preorder(Root)    print("***********************")    inorder(Root)    print("***********************")    postorder(Root)

图：用字典表示，每个元素是字典的键，元素指向的其他元素是值

# -*- coding:utf-8 -*-# file: pygraph.py#def generatePath(graph, path, end, results):    state=path[-1]    if state==end:        results.append(path)    else:        for arc in graph[state]:            if arc not in path:                generatePath(graph, path+[arc], end, results)def searchGraph(graph, start, end):    results=[]    generatePath(graph, [start], end, results)    results.sort(key=lambda x:len(x))    return resultsif __name__=="__main__":    Graph={ "A": ["B", "C" , "D"],            "B": ["E"],            "C": ["D", "F"],            "D": ["B", "E", "G"],            "E": [],            "F": ["D", "G"],            "G": ["E"]}    r=searchGraph(Graph, "A", "D")    for i in r:        print(i)

二分查找：必须已经排序好

# -*- coding:utf-8 -*-# file: pyBinarySearh.py#def BinarySearch(l, key):    low=0    high=len(l)-1    i=0    while(low<=high):        i=i+1        mid=(low+high)//2        if (l[mid]>key):            high=mid-1        elif (l[mid]<key):            low=mid+1        else:            print("use %d time(s)" % i)            return mid    return -1if __name__=="__main__":    l=[1,5,6,9,10,51,62,65,70]    print(BinarySearch(l,65))

二叉树排序：中序遍历是从小到大，从大到小则先从右子树开始进行中序遍历

# -*- coding:utf-8 -*-# file: pySort.py#class BTree:    def __init__(self, value):        self.left=None        self.data=value        self.right=None    def insertLeft(self, value):        self.left=BTree(value)        return self.left    def insertRight(self, value):        self.right=BTree(value)        return self.right    def show(self):        print(self.data)def inorder(node):    if node.data:                if node.left:            inorder(node.left)        node.show()        if node.right:            inorder(node.right)def rinorder(node):    if node.data:                if node.right:            rinorder(node.right)        node.show()        if node.left:            rinorder(node.left)def insert(node, value):    if value > node.data:        if node.right:            insert(node.right, value)        else:            node.insertRight(value)    else:        if node.left:            insert(node.left, value)        else:            node.insertLeft(value)if __name__=="__main__":    l=[3,5,7,20,43,2,15,30]    Root=BTree(l[0])    for i in range(1, len(l)):        insert(Root, l[i])    inorder(Root)    print("**********************")    rinorder(Root)

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