連結串列由一系列不必在記憶體中相連的結構構成，這些物件按線性順序排序。每個結構含有表元素和指向後繼元素的指標。最後一個單元的指標指向NULL。為了方便連結串列的刪除與插入操作，可以為連結串列新增一個表頭。
刪除操作可以通過修改一個指標來實現。
插入操作需要執行兩次指標調整。
1. 單向連結串列的實現
1.1 Node實現
每個Node分為兩部分。一部分含有連結串列的元素，可以稱為資料域；另一部分為一指標，指向下一個Node。
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class Node(): __slots__=['_item','_next'] #限定Node例項的屬性 def __init__(self,item): self._item=item self._next=None #Node的指標部分預設指向None def getItem(self): return self._item def getNext(self): return self._next def setItem(self,newitem): self._item=newitem def setNext(self,newnext): self._next=newnext |
1.2 SinglelinkedList的實現
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class SingleLinkedList(): def __init__(self): self._head=None #初始化連結串列為空表 self._size=0 |
1.3 檢測連結串列是否為空
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def isEmpty(self): return self._head==None |
1.4 add在連結串列前端新增元素
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def add(self,item): temp=Node(item) temp.setNext(self._head) self._head=temp |
1.5 append在連結串列尾部新增元素
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def append(self,item): temp=Node(item) if self.isEmpty(): self._head=temp #若為空表，將新增的元素設為第一個元素 else: current=self._head while current.getNext()!=None: current=current.getNext() #遍歷連結串列 current.setNext(temp) #此時current為連結串列最後的元素 |
1.6 search檢索元素是否在連結串列中
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def search(self,item): current=self._head founditem=False while current!=None and not founditem: if current.getItem()==item: founditem=True else: current=current.getNext() return founditem |
1.7 index索引元素在連結串列中的位置
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def index(self,item): current=self._head count=0 found=None while current!=None and not found: count+=1 if current.getItem()==item: found=True else: current=current.getNext() if found: return count else: raise ValueError,'%s is not in linkedlist'%item |
1.8 remove刪除連結串列中的某項元素
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def remove(self,item): current=self._head pre=None while current!=None: if current.getItem()==item: if not pre: self._head=current.getNext() else: pre.setNext(current.getNext()) break else: pre=current current=current.getNext() |
1.9 insert連結串列中插入元素
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def insert(self,pos,item): if posself.size(): self.append(item) else: temp=Node(item) count=1 pre=None current=self._head while count |
全部程式碼
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class Node(): __slots__=['_item','_next'] def __init__(self,item): self._item=item self._next=None def getItem(self): return self._item def getNext(self): return self._next def setItem(self,newitem): self._item=newitem def setNext(self,newnext): self._next=newnext class SingleLinkedList(): def __init__(self): self._head=None #初始化為空連結串列 def isEmpty(self): return self._head==None def size(self): current=self._head count=0 while current!=None: count+=1 current=current.getNext() return count def travel(self): current=self._head while current!=None: print current.getItem() current=current.getNext() def add(self,item): temp=Node(item) temp.setNext(self._head) self._head=temp def append(self,item): temp=Node(item) if self.isEmpty(): self._head=temp #若為空表，將新增的元素設為第一個元素 else: current=self._head while current.getNext()!=None: current=current.getNext() #遍歷連結串列 current.setNext(temp) #此時current為連結串列最後的元素 def search(self,item): current=self._head founditem=False while current!=None and not founditem: if current.getItem()==item: founditem=True else: current=current.getNext() return founditem def index(self,item): current=self._head count=0 found=None while current!=None and not found: count+=1 if current.getItem()==item: found=True else: current=current.getNext() if found: return count else: raise ValueError,'%s is not in linkedlist'%item def remove(self,item): current=self._head pre=None while current!=None: if current.getItem()==item: if not pre: self._head=current.getNext() else: pre.setNext(current.getNext()) break else: pre=current current=current.getNext() def insert(self,pos,item): if posself.size(): self.append(item) else: temp=Node(item) count=1 pre=None current=self._head while count |