单链表的实现：
分为java和python两种代码：
Python代码如下：
# -*- coding: utf-8 -*- ''' 利用python实现单向链表，单向链表由数据部分和下节点地址两部分组成 对于单向链表，首先要对每个链表元素创建一个类，属性包含数据部分和下节点地址部分。 然后再创建一个类来表示单向链表，单项列表主要包含，初始化，判断是否为空，追加节点，删除节点，插入节点，更新节点， 根据索引值获取数据项，根据数据项获取索引值，清空链表操作。 ''' # 定义单链表的节点Node类 class Node(object): def __init__(self, data, next=None): self.data = data self.next = next def __repr__(self): # 覆写了object中的__repr__，直接输出Node类对象即为调用了这个函数 return str(self.data) # 定义单链表类SingleChainTable class SingleChainTable(object): def __init__(self): self.head = None self. length = 0 def isEmpty(self): if self.length == 0: return True else: return False def append(self, dataOrNode): item = None # isinstance用来判断dataOrNode是否属于Node对象 # 如果是，直接接到链表末尾，如果不是，将其构建为一个节点接到链表末尾 if isinstance(dataOrNode, Node): item = dataOrNode else: item = Node(dataOrNode) # 首先要判断链表是否为空，如果为空，则直接把item赋给head # 否则，遍历链表找到最后一个节点 if self.head == None: self.head = item self.length += 1 else: node = self.head while node.next: node = node.next node.next = item self.length += 1 # 根据索引值来删除链表，首先要判断链表是否为空，索引值是否超出链表范围 # 如果以上两种情况都没出现，则查找索引值所对应的节点 # 如果index所指的是头节点，则直接将头节点head更改为原头节点的下一个节点，并将长度减去1即可。 # 如果index不是头节点，则需要遍历链表，找到index所对应的节点和其前一个节点，将前一个节点的next赋值为其后一个节点 def delete(self, index): if self.isEmpty(): print('the single 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 preNode = self.head while node.next and j < index: preNode = node node = node.next j += 1 if j == index: preNode.next = node.next self.length -= 1 return # 这里将插入理解为在某个索引值所对应的节点之前插入，因此需要找到index对应节点和其前一个节点 # 根据索引值插入节点，因此该函数需要一个索引值index，还需要一个节点对象dataOrNode # 因为有索引值，所以链表为空，不能插入，index也不能超过链表范围 # 首先判断index是否为0，为0，直接把数据作为表头，否则遍历寻找index所对用节点 def insert(self, index, dataOrNode): if self.isEmpty(): print('the single chain table 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 preNode = self.head node = self.head while node.next and j < index: preNode = node node = node.next j += 1 if j == index： preNode.next = item item.next = node self.length += 1 return # 更新索引值所对应节点的数据项 # 拥有索引值index，因此需要判断 def updata(self, index, data): if self.isEmpty(): print('the single chain table is empty.') return if 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 return # 根据索引值获取数据项 # 判断index def getItem(self, index): if self.isEmpty(): print('the single chain table is empty.') return if 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: return node.data # 判断数据项data是否在链表中，并返回index值 def getIndex(self, data): if self.isEmpty(): print('the single chain table is empty.') return j = 0 node = self.head while node: if node.data = data: return j else: node = node.next j += 1 if j == length: print('%s not found' % data) return def clear(self): self.head = None self.length = 0
Java代码如下：
public class SingleChainTable2 { private Node head; private int length; public SingleChainTable2() { this.head = null; this.length = 0; } public boolean isEmpty(){ if(this.length == 0){ return true; }else{ return false; } } public void append(Object dataOrNode){ Node item = null; if(dataOrNode instanceof Node){ item = (Node)dataOrNode; }else{ item = new Node(Integer.parseInt(dataOrNode.toString())); } if(this.isEmpty()){ this.head = item; this.length++; }else{ Node node = this.head; while(node.getNext() != null){ node = node.getNext(); } node.setNext(item); this.length++; } } public void delete(int index){ if(this.isEmpty()){ System.out.println("the single chain table is empty."); } if(index < 0 || index >= this.length){ System.out.println("error: out of index."); } if(index == 0){ this.head = this.head.getNext(); this.length--; } int j = 0; Node preNode = this.head; Node node = this.head; while(node.getNext() != null && j < index){ preNode = node; node = node.getNext(); j++; } if(j == index){ preNode.setNext(node.getNext()); this.length--; } } public void insert(int index, Object dataOrNode){ if(this.isEmpty()){ System.out.println("the single chain table is empty."); } if(index < 0 || index >= this.length){ System.out.println("error: out of index."); } Node item = null; if(dataOrNode instanceof Node){ item = (Node)dataOrNode; }else{ item = new Node(Integer.parseInt(dataOrNode.toString())); } if(index == 0){ item.setNext(this.head); this.head = item; this.length++; } int j = 0; Node preNode = this.head; Node node = this.head; while(node.getNext() != null && j < index){ preNode = node; node = node.getNext(); j++; } if(j == index){ preNode.setNext(item); item.setNext(node); this.length++; } } public void update(int index, int data){ if(this.isEmpty()){ System.out.println("the single chain table is empty."); } if(index < 0 || index >= this.length){ System.out.println("error: out of index."); } int j = 0; Node node = this.head; while(node.getNext() != null && j < index){ node = node.getNext(); j++; } if(j == index){ node.setData(data); } } public int getItem(int index){ if(this.isEmpty()){ System.out.println("the single chain table is empty."); return -11111; } if(index < 0 || index >= this.length){ System.out.println("error: out of index."); return -11111; } int j = 0; Node node = this.head; while(node.getNext() != null && j < index){ node = node.getNext(); j++; } return node.getData(); } public int getIndex(int data){ if(this.isEmpty()){ System.out.println("the single chain table is empty."); return -1111; } int j = 0; Node node = this.head; while(node != null){ if(node.getData() == data){ return j; }else{ node = node.getNext(); j++; } } if(j == length){ System.out.println(data + "not found."); } return -1111; } public void clear(){ this.head = null; this.length = 0; } } class Node extends Object{ private int data; private Node next; public void setData(int data){ this.data = data; } public void setNext(Node next){ this.next = next; } public int getData(){ return this.data; } public Node getNext(){ return this.next; } public Node(int data){ this.data = data; this.next = null; } public String toString(){ return "" + this.data; } }
Java和Python基本是一样的，只是语法上的不同，还有要注意，java中本类用this关键字，而python的本类用self关键字。
