C++ 模版类的单向循环链式线性表

基于之前做的单向链式线性表http://blog.csdn.net/shiwazone/article/details/47000191，改进下，实现了循环链表，相对应单向链表，循环链表将尾节点的指针域指向头节点，加入循环，可以让我们在查找某一个index的节点时，可以先判断一下位置和链表长度的关系，如果index处于链表的前半部分，我们可以从头节点遍历查找，如果处于后半部分，我们可以从尾节点往前查找，当然此时我们需要使用双向链表。双向链表的操作，下次给出吧！循环链表给了我们一种思路，如果我们在一个数据块中，加入一个或一些标志节点，我们可以判断我们需要的操作是在哪个区间，可以实现提高工作效率！

代码中重载了加号运算符，实现两个链表的相加。其实我们还可以有更多的操作，但是很多操作都是基于我们的插入删除操作的！所以我们在做数据结构分析的时候，我们要注意到插入和删除的通用性！

#pragma once#include <iostream>using namespace std;template<typename EleType>class CircleList{public:struct Node{EleType _data;Node* _next;Node(){ _next = nullptr; }Node(EleType data){ _data = data; _next = nullptr; }};CircleList();~CircleList();bool GetElem(EleType& e, int index = 1)const;//得到List中第index个元素，把元素的_data赋给e;bool InsertElem(const EleType e, int index = 1);//在List的第index个位置插入一个节点，节点的数据为ebool DeleteElem(EleType& e, int index = 1);//在List的第index个位置删除一个节点，删除节点的数据赋给ebool InsertHead(const EleType& e);//在头部插入数据bool InsertTail(const EleType& e);//在尾部插入数据bool Clear();//清空Listvoid ShowList()const;//显示List的所有元素的数据CircleList<EleType>* operator+(CircleList<EleType>& addList);//重载运算符private:bool Empty()const;//判断List是否为空CircleList<EleType>* AddList(CircleList<EleType>& addList);//加上addList的数据，相当于把addList的数据从尾部插入到原List中//在List中查找第index个位置的节点，把该节点的地址赋给n，此处需传入指针的引用，才能保证n可以被修改，不然只能保证*n可以被修改，也就是n指向的节点可以被修改bool Find(int index, Node*& n)const;bool CheckIndex(int index)const;//检查List是否为空，index是否合法Node* Head;//头指针Node* Tail;//尾指针int Length;};

#include "CircleList.h"#include <iostream>using namespace std;template<typename EleType>bool CircleList<EleType>::CheckIndex(int index) const{if (Empty()){cout << "Find: the List is Empty!\n";return false;}if (index<1 || index>Length){cout << "the index is invalid!\n";return false;}return true;}template<typename EleType>bool CircleList<EleType>::Find(int index, Node*& n)const//index [1,Length];{if (CheckIndex(index)){int i = 1;Node * temp = Head;while (i < index){temp = temp->_next;++i;}n = temp;return true;}return false;}template<typename EleType>void CircleList<EleType>::ShowList() const{Node * temp = nullptr;if (Empty()){cout << "The list is empty!\n";}else{for (int i = 1; i <= Length ; ++i){Find(i, temp);cout << temp->_data << " ";}cout << endl;}}template<typename EleType>bool CircleList<EleType>::Clear(){if (Empty()){return true;}else{while (Length){EleType m;DeleteElem(m);}return true;}}template<typename EleType>bool CircleList<EleType>::DeleteElem(EleType& e, int index = 1){if (CheckIndex(index)){Node* temp = nullptr;Node* pre_temp = nullptr;if (Find(index, temp)){if (index == 1){Find(index + 1, Head);}else{if (index == Length){Find(index - 1, Tail);}else{Find(index - 1, pre_temp);pre_temp->_next = temp->_next;}}e = temp->_data;delete temp;--Length;return true;}return false;}return false;}template<typename EleType>bool CircleList<EleType>::InsertElem(const EleType e, int index){Node *insertNode = new Node(e);if (Empty()){if (index < 1) return false;Head = Tail = insertNode;insertNode->_next = insertNode;++Length;return true;}if (index == 1){insertNode->_next = Head;Head = insertNode;Tail->_next = Head;++Length;return true;}if (index == Length + 1){Tail->_next = insertNode;insertNode->_next = Head;Tail = insertNode;++Length;return true;}Node  *temp = nullptr;if (Find(index - 1, temp)){insertNode->_next = temp->_next;temp->_next = insertNode;++Length;return true;}return false;}template<typename EleType>bool CircleList<EleType>::GetElem(EleType& e, int index) const{if (CheckIndex(index)){Node* temp = nullptr;if (Find(index, temp))e = temp->_data;return true;}return false;}template<typename EleType>CircleList<EleType>::~CircleList(){Clear();}template<typename EleType>CircleList<EleType>::CircleList() :Length(0), Head(nullptr), Tail(nullptr){}template<typename EleType>bool CircleList<EleType>::Empty() const{return(Length == 0);}template<typename EleType>bool CircleList<EleType>::InsertTail(const EleType& e){return InsertElem(e, Length + 1);}template<typename EleType>bool CircleList<EleType>::InsertHead(const EleType& e){return InsertElem(e);}template<typename EleType>CircleList<EleType>* CircleList<EleType>::AddList(CircleList<EleType>& addList){if (Empty()){if (addList.Empty()){return this;}Node* temp = addList.Head;for (int i = 1; i <= addList.Length;++i){InsertTail(temp->_data);temp = temp->_next;}return this;}else{if (addList.Empty()){return this;}else{Node* temp = addList.Head;for (int i = 1; i <= addList.Length; ++i){InsertTail(temp->_data);temp = temp->_next;}return this;}}}template<typename EleType>CircleList<EleType>* CircleList<EleType>::operator+(CircleList<EleType>& addList){return AddList(addList);}

#include "CircleList.cpp"int main(){CircleList<int> IntList1;IntList1.ShowList();IntList1.InsertElem(155);IntList1.InsertElem(5);IntList1.InsertElem(55);IntList1.InsertElem(15);IntList1.InsertElem(99);IntList1.ShowList();CircleList<int> IntList2;IntList2.InsertElem(11);IntList2.InsertElem(11);IntList2.InsertElem(11);IntList2.InsertElem(11);IntList2.InsertElem(11);IntList2.ShowList();CircleList<int> *IntList3;IntList3 = IntList2 + IntList1;IntList3->ShowList();return 0;}