LinkedList.h

//單向連結串列的實現 //查詢、插入和移除某個元素、複製、清空單向連結串列的時間複雜度均為O(n) //設計類時，應儘量減少類的成員函式之間的依賴關係 #ifndef LINKEDLIST_H #define LINKEDLIST_H template<class DT> struct Node { DT info; Node<DT> *next; }; template<class DT> class LinkedList { public: LinkedList(); LinkedList(const LinkedList<DT> &aplist); ~LinkedList(); LinkedList<DT>& operator=(const LinkedList<DT> &rlist); void insert(const DT &element); //在連結串列的頭部之前插入 void insert_end(const DT &element); //在連結串列的尾部插入 bool first(DT &listEl); //得到對頭的資料 inline bool getNext(DT &listEl); //得到當前指標所指的下一個資料 bool find(const DT &element); //查詢一個數據 bool retrieve(DT &element); //檢索一個數據 bool replace(const DT &newElement); //更改一個數據 bool remove(DT &element); bool isEmpty() const; void makeEmpty(); private: Node<DT> *start; //指向頭結點 Node<DT> *current; //指向當前的結點 inline void deepCopy(const LinkedList<DT> &original); //"深複製" }; #endif

LinkedList.cpp

#include "LinkedList.h" template<class DT> LinkedList<DT>::LinkedList() { start = current = NULL; } template<class DT> LinkedList<DT>::LinkedList(const LinkedList<DT> &aplist) { deepCopy(aplist); } template<class DT> LinkedList<DT>::~LinkedList() { makeEmpty(); } template<class DT> LinkedList<DT>& LinkedList<DT>::operator =(const LinkedList<DT> &rlist) { if(this == &rlist) return this; makeEmpty(); deepCopy(rlist); return this; } //在連結串列的表頭插入DT &element，插入後沒有當前位置 template<class DT> void LinkedList<DT>::insert(const DT &element) { current = NULL; Node<DT> *NNode = new Node<DT>; NNode->info = element; NNode->next = start; start = NNode; } ////在連結串列的尾部插入 template<class DT> void LinkedList<DT>::insert_end(const DT &element) { current = NULL; Node<DT> *NNode = new Node<DT>; NNode->info = element; NNode->next = NULL; Node<DT> *temp; DT item; if(start == NULL) { start = NNode; temp = start; return; } temp = start; while(temp->next != NULL) { temp = temp->next; } temp->next = NNode; } //把連結串列中的第一個元素存放在listEl中，並且把第一個元素的位置置為current template<class DT> bool LinkedList<DT>::first(DT &listEl) { if(start == NULL) return false; current = start; listEl = start->info; return true; } //把連結串列中current的下個元素放在listEl中，current指向下一個元素 template<class DT> bool LinkedList<DT>::getNext(DT &listEl) { if(current == NULL) return false; if(current->next == NULL) { current = NULL; return false; } listEl = current->next->info; current = current->next; return true; } //如果找到elment，返回true,current在getNext()中設定 template<class DT> bool LinkedList<DT>::find(const DT &element) { DT item; if(!first(item)) return false; //檢查是否為空 do{ if(item == element) return true; }while(getNext(item)); return false; } template<class DT> bool LinkedList<DT>::retrieve(DT &element) { if(!find(element)) return false; element = current->info; return true; } template<class DT> bool LinkedList<DT>::replace(const DT &newElement) { if(current == NULL) return false; current->info = newElement; return true; } template<class DT> bool LinkedList<DT>::remove(DT &element) { current = NULL; if(start == NULL) return false; Node<DT> *ptr = start; if(start->info == element) { element = start->info; start = ptr->next; delete ptr; return true; } while(ptr->next != NULL){ if(ptr->next->info == element) { Node<DT> *tempptr = ptr->next; element = tempptr->info; ptr->next = tempptr->next; delete tempptr; return true; } ptr = ptr->next; } return false; } template<class DT> bool LinkedList<DT>::isEmpty() const { return start == NULL; } template<class DT> void LinkedList<DT>::makeEmpty() { while(start != NULL) { current = start; start = start->next; delete current; } current = NULL; } template<class DT> void LinkedList<DT>::deepCopy(const LinkedList<DT> &original) { start = current = NULL; if(original.start == NULL) return; Node<DT> *copyptr = start = new Node<DT>; Node<DT> *originalptr = original.start; copyptr->info = originalptr->info; if(originalptr == original.current) current = copyptr; while(originalptr->next != NULL) { copyptr->next = new Node<DT>; //這一句有難度啊！ originalptr = originalptr->next; copyptr = copyptr->next; copyptr->info = originalptr->info; if(originalptr == original.current) current = copyptr; } copyptr->next = NULL; } //#endif

測試用例：

#include<iostream> #include "LinkedList.cpp" #include<string> using namespace std; void main() { string str[5] = {"hello","world","welcome","to","beijing"}; //初始化一個連結串列 LinkedList<string> strLL; for(int ix=0;ix<5;++ix) // strLL.insert(str[ix]); //呼叫insert()，依次插入在連結串列的頭部 strLL.insert_end(str[ix]); //遍歷連結串列 cout<<"遍歷連結串列: "; string listEl; if(strLL.first(listEl)) cout<<listEl<<" "; //獲得current while(strLL.getNext(listEl)) cout<<listEl<<" "; cout<<endl; LinkedList<string> strLL2(strLL); //呼叫建構函式初始化 LinkedList<string> strLL3 = strLL; //呼叫過載“=”操作符 strLL2.first(listEl); cout<<"ListEl = "<<listEl<<endl; strLL3.first(listEl); cout<<"ListEl = "<<listEl<<endl; if(strLL2.find(str[3])) //呼叫find() cout<<"str[3] = "<<str[3]<<endl; if(strLL3.retrieve(str[2])) //呼叫retrieve() cout<<"str[2] = "<<str[2]<<endl; if(strLL.remove(str[1])) { strLL.first(listEl); cout<<"ListEl after remove is "<<listEl<<endl; } if(strLL.isEmpty()) cout<<"List is Empty!"<<endl; strLL.makeEmpty(); strLL2.makeEmpty(); strLL3.makeEmpty(); cout<<"hello"<<endl; }