[C++] 模版双向鍊表

 

 

#include <iostream>template <typename T>class double_linked{ struct node { T data; node* prev; node* next; node(T t, node* p, node* n) : data(t), prev(p), next(n) {} }; node* head; node* tail;public: double_linked() : head( NULL ), tail ( NULL ) {} template<int N> double_linked( T (&arr) [N]) : head( NULL ), tail ( NULL ) { for( int i(0); i != N; ++i) push_back(arr[i]); } bool empty() const { return ( !head || !tail ); } operator bool() const { return !empty(); } void push_back(T); void push_front(T); T pop_back(); T pop_front(); ~double_linked() { while(head) { node* temp(head); head=head->next; delete temp; } }};template <typename T>void double_linked<T>::push_back(T data){ tail = new node(data, tail, NULL); if( tail->prev ) tail->prev->next = tail; if( empty() ) head = tail;}template <typename T>void double_linked<T>::push_front(T data){ head = new node(data, NULL, head); if( head->next ) head->next->prev = head; if( empty() ) tail = head;}template<typename T>T double_linked<T>::pop_back(){ if( empty() ) throw("double_linked : list empty"); node* temp(tail); T data( tail->data ); tail = tail->prev ; if( tail ) tail->next = NULL; else head = NULL ; delete temp; return data;}template<typename T>T double_linked<T>::pop_front(){ if( empty() ) throw("double_linked : list empty"); node* temp(head); T data( head->data ); head = head->next ; if( head ) head->prev = NULL; else tail = NULL; delete temp; return data;}int main(){ int arr[] = { 4, 6, 8, 32, 19 } ; double_linked<int> dlist ( arr ); dlist.push_back( 11 ); dlist.push_front( 100 ); while( dlist ) std::cout << dlist.pop_back() << " ";}