Python数据结构与算法之链表定义与用法实例详解【单链表、循环链
本篇章节讲解Python数据结构与算法之链表定义与用法。分享给大家供大家参考,具体如下: 本文将为大家讲解: (1)从链表节点的定义开始,以类的方式,面向对象的思想进行链表的设计 (2)链表类插入和删除等成员函数实现时需要考虑的边界条件, 2.1 插入: 空链表 2.2 删除 空链表 (3)从单链表到单链表的一众变体: 带尾节点的单链表 1. 链表节点的定义 class LNode: def __init__(self,elem,next_=None): self.elem = elem self.next = next_ 2. 单链表的实现 重点理解插入、删除的实现及其需要考虑的边界条件: class LinkedListUnderflow(ValueError): pass class LList: def __init__(self): self._head = None def is_empty(self): return self._head is None def prepend(self,elem): self._head = LNode(elem,self._head) def pop(self): if self._head is None: raise LinkedListUnderflow('in pop') e = self._head.elem self._head = self._head.next return e def append(self,elem): if self._head is None: self._head = LNode(elem) return p = self._head while p.next is not None: p = p.next p.next = LNode(elem) def pop_last(self): if self._head is None: raise LinkedListUnderflow('in pop_last') p = self._head if p.next is None: e = p.elem self._head = None return e while p.next.next is not None: p = p.next e = p.next.elem p.next = None return e 简单总结: (0)能够访问 p.next.next 的前提是 p.next 不为空; 单链表的简单变形:具有尾部节点的单链表 class LList1(LList): def __init__(self): LList.__init__(self) self._rear = None ... 我们仅需重写的是:头部的插入、尾部的插入、尾部的删除 def prepend(self,elem): if self._head is None: self._head = LNode(elem) self._rear = self._head else: self._head = LNode(elem,self._head) def append(self,elem): if self._head is None: self._head = LNode(elem) self._rear = self._head else: self._rear.next = LNode(elem) self._rear = self._rear.next def pop_last(self): if self._head is None: raise LinkedListUnderflow('in pop_last') p = self._head if p.next is None: e = p.elem self._head = None return e while p.next.next is not None: p = p.next e = p.next.elem self._rear = p p.next = None return e 单链表的变体:循环单链表 class LCList: def __init__(self): self._rear = None def prepend(self,elem): if self._rear is None: self._rear = LNode(elem) self._rear.next = self._rear else: self._rear.next = LNode(elem,self._rear.next) def append(self,elem): self.prepend(elem) self_rear = self._rear.next def pop(self): if self._rear is None: raise LinkedListUnderflow('in pop') p = self._rear.next if p is None: self._rear = None else: self._rear.next = p.next return p.elem def printall(self): if self._rear is None: raise ... p = self._rear.next while True: print(p.elem) if p is self._rear: break p = p.next 更多关于Python相关内容可查看本站专题:《Python数据结构与算法教程》、《Python Socket编程技巧总结》、《Python函数使用技巧总结》、《Python字符串操作技巧汇总》、《Python入门与进阶经典教程》及《Python文件与目录操作技巧汇总》 希望本文所述对大家Python程序设计有所帮助。 (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |