C++實現雙鏈表node
實現代碼
雙向鏈表文件(DoubleLink.h)ios
#ifndef DOUBLE_LINK_HXX #define DOUBLE_LINK_HXX #include <iostream> using namespace std; template<class T> struct DNode { public: T value; DNode *prev; DNode *next; public: DNode() { } DNode(T t, DNode *prev, DNode *next) { this->value = t; this->prev = prev; this->next = next; } }; template<class T> class DoubleLink { public: DoubleLink(); ~DoubleLink(); int size(); int is_empty(); T get(int index); T get_first(); T get_last(); int insert(int index, T t); int insert_first(T t); int append_last(T t); int del(int index); int delete_first(); int delete_last(); private: int count; DNode<T> *phead; private: DNode<T> *get_node(int index); }; template<class T> DoubleLink<T>::DoubleLink() : count(0) { // 建立「表頭」。注意:表頭沒有存儲數據! phead = new DNode<T>(); phead->prev = phead->next = phead; // 設置鏈表計數爲0 //count = 0; } // 析構函數 template<class T> DoubleLink<T>::~DoubleLink() { // 刪除全部的節點 DNode<T>* ptmp; DNode<T>* pnode = phead->next; while (pnode != phead) { ptmp = pnode; pnode=pnode->next; delete ptmp; } // 刪除"表頭" delete phead; phead = NULL; } // 返回節點數目 template<class T> int DoubleLink<T>::size() { return count; } // 返回鏈表是否爲空 template<class T> int DoubleLink<T>::is_empty() { return count==0; } // 獲取第index位置的節點 template<class T> DNode<T>* DoubleLink<T>::get_node(int index) { // 判斷參數有效性 if (index<0 || index>=count) { cout << "get node failed! the index in out of bound!" << endl; return NULL; } // 正向查找 if (index <= count/2) { int i=0; DNode<T>* pindex = phead->next; while (i++ < index) { pindex = pindex->next; } return pindex; } // 反向查找 int j=0; int rindex = count - index -1; DNode<T>* prindex = phead->prev; while (j++ < rindex) { prindex = prindex->prev; } return prindex; } // 獲取第index位置的節點的值 template<class T> T DoubleLink<T>::get(int index) { return get_node(index)->value; } // 獲取第1個節點的值 template<class T> T DoubleLink<T>::get_first() { return get_node(0)->value; } // 獲取最後一個節點的值 template<class T> T DoubleLink<T>::get_last() { return get_node(count-1)->value; } // 將節點插入到第index位置以前 template<class T> int DoubleLink<T>::insert(int index, T t) { if (index == 0) return insert_first(t); DNode<T>* pindex = get_node(index); DNode<T>* pnode = new DNode<T>(t, pindex->prev, pindex); pindex->prev->next = pnode; pindex->prev = pnode; count++; return 0; } // 將節點插入第一個節點處。 template<class T> int DoubleLink<T>::insert_first(T t) { DNode<T>* pnode = new DNode<T>(t, phead, phead->next); phead->next->prev = pnode; phead->next = pnode; count++; return 0; } // 將節點追加到鏈表的末尾 template<class T> int DoubleLink<T>::append_last(T t) { DNode<T>* pnode = new DNode<T>(t, phead->prev, phead); phead->prev->next = pnode; phead->prev = pnode; count++; return 0; } // 刪除index位置的節點 template<class T> int DoubleLink<T>::del(int index) { DNode<T>* pindex = get_node(index); pindex->next->prev = pindex->prev; pindex->prev->next = pindex->next; delete pindex; count--; return 0; } // 刪除第一個節點 template<class T> int DoubleLink<T>::delete_first() { return del(0); } // 刪除最後一個節點 template<class T> int DoubleLink<T>::delete_last() { return del(count-1); } #endif