[剑指offer][从头到尾打印链表]Python2.7实现/用python实现链表并测试

class Node(object):
    def __init__(self, data, pnext = None):
        self.data = data
        self.next = pnext


    def __repr__(self):
        return str(self.data)


class ChainTable(object):
    def __init__(self):
        self.head = None
        self.length = 0

    #判断链表是否为空
    def isEmpty(self):
        return (self.length == 0)

    #添加链表元素
    def append(self, dataOrNode):
        item = None
        if isinstance(dataOrNode, Node):
            item = dataOrNode
        else:
            item = Node(dataOrNode)


        if not self.head:
            self.head = item
            self.length += 1


        else:
            node = self.head
            while node.next:
                node = node.next
            node.next = item
            self.length += 1

    #删除链表元素
    def delete(self, index):
        if self.isEmpty():
            print "this chain table is empty."
            return


        if index < 0 or index >= self.length:
            print 'error: out of index'
            return


        if index == 0:
            self.head = self.head.next
            self.length -= 1
            return


        j = 0
        node = self.head
        prev = self.head
        while node.next and j < index:
            prev = node
            node = node.next
            j += 1


        if j == index:
            prev.next = node.next
            self.length -= 1

    #插入链表元素
    def insert(self, index, dataOrNode):
        if self.isEmpty():
            print "this chain tabale is empty"
            return


        if index < 0 or index >= self.length:
            print "error: out of index"
            return


        item = None
        if isinstance(dataOrNode, Node):
            item = dataOrNode
        else:
            item = Node(dataOrNode)


        if index == 0:
            item.next = self.head
            self.head = item
            self.length += 1
            return


        j = 0
        node = self.head
        prev = self.head
        while node.next and j < index:
            prev = node
            node = node.next
            j += 1


        if j == index:
            item.next = node
            prev.next = item
            self.length += 1

    #更新某元素
    def update(self, index, data):
        if self.isEmpty() or index < 0 or index >= self.length:
            print 'error: out of index'
            return
        j = 0
        node = self.head
        while node.next and j < index:
            node = node.next
            j += 1


        if j == index:
            node.data = data

    #获取链表内容
    def getItem(self, index):
        if self.isEmpty() or index < 0 or index >= self.length:
            print "error: out of index"
            return
        j = 0
        node = self.head
        while node.next and j < index:
            node = node.next
            j += 1


        return node.data



    #查找某元素位置
    def getIndex(self, data):
        j = 0
        if self.isEmpty():
            print "this chain table is empty"
            return
        node = self.head
        while node:
            if node.data == data:
                return j
            node = node.next
            j += 1


        if j == self.length:
            print "%s not found" % str(data)
            return

    #清空链表
    def clear(self):
        self.head = None
        self.length = 0

    
    def __repr__(self):
        if self.isEmpty():
            return "empty chain table"
        node = self.head
        nlist = ''
        while node:
            nlist += str(node.data) + ' '
            node = node.next
        return nlist


    def __getitem__(self, ind):
        if self.isEmpty() or ind < 0 or ind >= self.length:
            print "error: out of index"
            return
        return self.getItem(ind)


    def __setitem__(self, ind, val):
        if self.isEmpty() or ind < 0 or ind >= self.length:
            print "error: out of index"
            return
        self.update(ind, val)


    def __len__(self):
        return self.length


class Solution:  
    def printListFromTailToHead(self, Node):  
        out = []  
        if Node is None:  
            return out  
        while Node.next is not None:  
            out.append(Node.data)  
            Node = Node.next  
        out.append(Node.data)  
        out.reverse()  
        return out  
        
lianbiao = ChainTable()

#创建链表

for i in range(9):

    lianbiao.append(i)
print lianbiao

#从头到尾打印链表

s = Solution()
l = s.printListFromTailToHead(lianbiao.head)
for i in l:
    print i