Two-way linked list with leading tail node

#include <iostream> #include <assert.h>using namespace std;typedef int datatype;/ /doubly linked list, headless node struct linknode{//struct default is the public Access qualifier Public:linknode (const datatype& x): _data (x),  _prev (NULL),  _next (null) {}~linknode () {}public:datatype _data; linknode* _prev; linknode* _next;}; Class list{public:list (): _head (null),  _tail (null) {}~list () {}void pushback (const datatype & x) {linknode* tmp = new linknode (x);if  (null == _tail) {_head  = _tail=tmp;} Else{tmp->_prev = _tail;_tail->_next = tmp;_tail = _tail->_next;}} Void  popback () {linknode* cur = _head;if  (_tail == null) {return;} elseif  (_head == _tail) {delete _head;_head = _tail = null;} else{linknode* del = _tail;_tail->_prev->_next = null;_tail = _tail- >_prEv;delete del;}} Void pushfront (const datatype& x) {linknode* tmp = new linknode (x);// If there is no node if  (null== _tail) {_tail=_head = tmp;} Else {tmp->_next = _head;_head->_prev = tmp;_head = tmp;}} Void popfront () {if  (_head == null) return;else if  (_head==_tail) {free (_head); _ Head = _tail=null;} else{linknode* del = _head;_head = _head->_next;_head->_prev = null; Delete del;}} Linknode* find (const datatype& x) {linknode* cur = _head;while  (cur) {if   (cur->_data == x) Return cur;cur = cur->_next;} Return null;} Void erase (Linknode* pos) {assert (POS);//Processing POS is header, tail or head and tail linknode* del = null;if  ( Pos == _head) {Del = pos;_head = _head->_next;_head->_prev = null ;} if  (Pos==_taIL) {del = pos;_tail = _tail->_prev;_tail->_next = null;} if  (del == null) {linknode* prev = pos->_prev; Linknode* next = pos->_next;prev->_next = next;next->_prev = prev;} Delete del;} Void insert (linknode* pos, const datatype& x) {assert (POS); Linknode* tmp = new linknode (x);if  (pos == _tail) {_tail->_next =  tmp;tmp->_prev = _tail;_tail = tmp;} else{linknode* next = pos->_next;tmp->_next = next;next->_prev =  Tmp;pos->_next = tmp;tmp->_prev = pos;}} Void  display () {linknode* cur = _head;while  (cur) {cout <<  (cur- >_data)  <<  ", Cur = cur->_next;} cout <<  "NULL" &NBSP;&LT;&LT;&NBSP;ENDL;} private:linknode* _head; Linknode* _tail;}; Void test1 () {list l1;l1. Pushback (1); L1. Pushback (2); L1. Pushback (3); L1. Pushback (4); L1. Pushback (5); L1. Pushback (6); L1. DisPlay (); L1. Popback (); L1. DisPlay (); L1. Popback (); L1. Popback (); L1. Popback (); L1. Popback (); L1. Popback (); L1. Popback (); L1. Popback (); L1. Popback (); L1. DisPlay ();} Void test2 () {list l2;l2. Pushfront (1); L2. Pushfront (2); L2. Pushfront (3); L2. Pushfront (4); L2. Pushfront (5); L2. Pushfront (6); L2. DisPlay (); L2. Popfront (); L2. Popfront (); L2. Popfront (); L2. Popfront (); L2. DisPlay (); L2. Popfront (); L2. Popfront (); L2. Popfront (); L2. Popfront (); L2. DisPlay ();} Void test3 () {list l2;l2. Pushfront (1); L2. Pushfront (2); L2. Pushfront (3); L2. Pushfront (4); L2. Pushfront (5); L2. Pushfront (6); L2. DisPlay (); Linknode* ret = l2. Find (6);//l2. Erase (ret); L2. Insert (ret, 7); L2. DisPlay ();} Int main () {Test3 (); System ("pause"); return 0;}

This article is from the "Small Stop" blog, please be sure to keep this source http://10541556.blog.51cto.com/10531556/1717933

Two-way linked list with leading tail node