python-单链表的实现

  1  #!/usr/bin/python
  2 
  3 class Node(object):
  4     def __init__(self,value,next=None):
  5         self.value,self.next=value,next
  6 
  7 class Linklist(object):
  8     def __init__(self):
  9         self.head=None
 10     def initlist(self,data):
 11         self.head=Node(0)
 12         p=self.head
 13 
 14         for i in data:
 15             node=Node(i)
 16             p.next=node
 17             p=p.next
 18 
 19     def show(self):
 20         p=self.head.next
 21         while p!=None:
 22             print p.value
 23             p=p.next
 24     def getlength(self):
 25         p=self.head
 26         length=0
 27 
 28         while p.next !=None:
 29             length+=1
 30             p=p.next
 31         return length
 32 
 33     def insert(self,index,value):
 34         if index<0 or index>self.getlength():
 35             print "Index is Error!"
 36             return
 37         p=self.head   
 38         j=0
 39         while p.next !=None and j < index:
 40             p=p.next
 41             j+=1
 42         node=Node(value,p.next)
 43         p.next=node
 44     
 45 
 46     def remove(self,index):
 47         if index<0 or index > self.getlength():
 48             print "Index is Error!"
 49             return 
 50 
 51         p=self.head
 52         j=0
 53         while p.next !=None and j<index:
 54             p=p.next
 55             j+=1
 56         next=p.next.next
 57     
 58     def checkin(self,value):
 59         p=self.head
 60         flag=-1
 61         while p.next != None:
 62             if p.next.value==value:
 63                 flag=1
 64                 return flag 
 65             p=p.next
 66         return flag  
 67 
 68     def replace(self,index,value):
 69         p=self.head.next
 70         i=0
 71         while i<index:
 72             p=p.next
 73             i+=1
 74         p.value=value
 75     
 76     def getitem(self,index):
 77         p=self.head.next
 78         j=0
 79         while p!=None and j<index:
 80             j+=1
 81             p=p.next
 82         return p.value
 83 
 84     def is_empty(self):
 85         if self.getlength()==0:
 86             return True
 87         else:
 88             return False
 89 
 90     def __getitem__(self,key):
 91         if self.is_empty() or key>=self.getlength():
 92             print "Index is Error!"
 93             return
 94         else:
 95             return self.getitem(key)
 96     def __setitem__(self,key,value):
 97         if self.is_empty() or key>=self.getlength():
 98             print "Index is Error!"
 99             return
100         else:
101             return self.replace(key,value)