Python实现数据结构线性链表（单链表）算法示例

#!/usr/bin/python
# -*- coding:utf-8 -*-
# Author: Hui
# Date:  2017-10-13
# 结点类，
class Node:
  def __init__(self, data):
    self.data = data      # 数据域
    self.next = None      # 指针域
  def get_data(self):
    return self.data
# 链表类
class List:
  def __init__(self, head):
    self.head = head      # 默认初始化头结点
  def is_empty(self):     # 空链表判断
    return self.get_len() == 0
  def get_len(self):     # 返回链表长度
    length = 0
    temp = self.head
    while temp is not None:
      length += 1
      temp = temp.next
    return length
  def append(self, node):     # 追加结点（链表尾部追加）
    temp = self.head
    while temp.next is not None:
      temp = temp.next
    temp.next = node
  def delete(self, index):      # 删除结点
    if index < 1 or index > self.get_len():
      print "给定位置不合理"
      return
    if index == 1:
      self.head = self.head.next
      return
    temp = self.head
    cur_pos = 0
    while temp is not None:
      cur_pos += 1
      if cur_pos == index-1:
        temp.next = temp.next.next
      temp = temp.next
  def insert(self, pos, node):     # 插入结点
    if pos < 1 or pos > self.get_len():
      print "插入结点位置不合理..."
      return
    temp = self.head
    cur_pos = 0
    while temp is not Node:
      cur_pos += 1
      if cur_pos == pos-1:
        node.next = temp.next
        temp.next =node
        break
      temp = temp.next
  def reverse(self, head):     # 反转链表
    if head is None and head.next is None:
      return head
    pre = head
    cur = head.next
    while cur is not None:
      temp = cur.next
      cur.next = pre
      pre = cur
      cur = temp
    head.next = None
    return pre
  def print_list(self, head):      # 打印链表
    init_data = []
    while head is not None:
      init_data.append(head.get_data())
      head = head.next
    return init_data
if __name__ == '__main__':
  head = Node("head")
  list = List(head)
  print '初始化头结点：\t', list.print_list(head)
  for i in range(1, 10):
    node = Node(i)
    list.append(node)
  print '链表添加元素：\t', list.print_list(head)
  print '链表是否空：\t', list.is_empty()
  print '链表长度：\t', list.get_len()
  list.delete(9)
  print '删除第9个元素:\t',list.print_list(head)
  node = Node("insert")
  list.insert(3, node)
  print '第3个位置插入‘insert'字符串 :\t', list.print_list(head)
  head = list.reverse(head)
  print '链表反转：', list.print_list(head)