(with head and tail pointers) the realization of various functions of cyclic doubly linked list

The following functions are implemented for circular doubly linked lists:

void Meau ();                           menu function void Initlist (List *list);             initialize void Show (List *list);                 Print List contents bool Push_back (list *list,elemtype x); Tail interpolation method bool Push_front (list *list,elemtype x);//head interpolation bool Isempty (list *list);              Determines whether the linked list is an empty bool Pop_back (list *list);             Tail-censored bool Pop_front (List *list);            Head Delete node *find_val (List *list,elemtype x); find bool Delete_val by value (list *list,elemtype x);//delete bool Modify by value (list *list,elemtype x);    Modify void Clear (List *list);                Empty list void Destory (list *list);              Destroy linked list void reverse (list *list);              Reverse linked list node *prio (list *list,elemtype x);     The predecessor Node *next (List *list,elemtype x) that asks for a value;     The subsequent bool Insert_val (list *list,elemtype x) for a value, and//insert void sort (list *list) by value;                 Sort (Ascending)

DCList.h:

#ifndef __dclist_h__#define __dclist_h__#include<assert.h> #include <iostream>using namespace std; typedef int ELEMTYPE;TYPEDEF struct NODE{STRUCT node *pre;struct node *next; Elemtype data;} node;typedef struct List{node *first; Node *last;int size;}                           List;void Meau ();             menu function void Initlist (List *list);                 initialize void Show (List *list); Print List contents bool Push_back (list *list,elemtype x);              Tail interpolation method bool Push_front (list *list,elemtype x);//head interpolation bool Isempty (list *list);             Determines whether the linked list is an empty bool Pop_back (list *list);            Tail-censored bool Pop_front (List *list); Head Delete node *find_val (List *list,elemtype x);    find bool Delete_val by value (list *list,elemtype x);//delete bool Modify by value (list *list,elemtype x);                Modify void Clear (List *list);              Empty list void Destory (list *list);              Destroy linked list void reverse (list *list);     Reverse linked list node *prio (list *list,elemtype x);     The predecessor Node *next (List *list,elemtype x) that asks for a value; The subsequent bool insert_v of a valueAl (list *list,elemtype x);//insert void sort (list *list) by value; Sort (Ascending) #endif

DCList.cpp:

#include "DCList.h"/* Menu function */void Meau () {cout<< "*****************seqlist********************" <<endl; cout<< "---zyh_helen" <<endl;cout<< "*[1]initseqlist [2]push_b                ACK * "<<endl;cout<<" *[3]push_front [4]pop_back * "<<endl;cout<<" *[5]pop_front [6]                   Find_val * "<<endl;cout<<" *[7]show [0]quit_syatem* "<<endl;cout<<" *[8]modify [9] Delete_val * "<<endl; cout<< "*[10]clear [11]destory *" <<endl;      cout<< "*[12]reverse [13]prio *" <<endl;cout<< "*[14]next [15]sort * "<<endl;cout<<" *[16]insert_val * "&LT;&LT;ENDL;} /* Initialize linked list */void initlist (List *list) {Node *s = (node *) malloc (sizeof); assert (s! = NULL); s->next = S->pre = S;lis T->first = List->last = S;list->size = 0;} /* Tail interpolation method*/bool push_back (List *list,elemtype x) {Node *s = (node *) malloc (sizeof); if (s! = NULL) {s->data = X;list->last ->next = S;s->pre = List->last;list->last = S;list->last->next = list->first;list->first-> Pre = List->last;//s->next = List->first;//list->last = S;list->size++;return true;} Elsereturn false;} /* Print List Contents */void Show (List *list) {Node *s = List->first->next;while (s! = List->first) {Cout<<s->data << "--"; s = s->next;} cout<< "NULL" &LT;&LT;ENDL;} /* Header interpolation */bool push_front (List *list,elemtype x) {Node *s = (node *) malloc (sizeof (node)), if (s! = NULL) {S->data = x;/* and later elements (Original first element) connection */s->next = List->first->next;list->first->next->pre = s;/* and head node connection */list->first- >next = S;s->pre = list->first;/* If the first node, the tail pointer should point to it */if (list->size = = 0) {List->last = s;} List->size++;return true;} else{cout<< "Application space failed! "<<endl;return false;}} /* Determine if the linked list is empty */bool Isempty (List *list) {return (LIST->size = = 0);} /* Tail-Erase */bool pop_back (list *list) {if (Isempty (list)) {cout<< "linked list is empty! "<<endl;return false;} Node *s = list->last->pre;//Find the last node's precursor free (list->last);//Release last node/* Connection */s->next = list->first;list- >last = S;list->size--;return true;} BOOL Pop_front (list *list) {if (Isempty (list)) {cout<< "linked list is empty! "<<endl;return false;} Node *s = list->first->next;//Find the first node (to be freed)/* Connection */list->first->next = S->next;s->next->pre = list->first;/* if the node to be deleted is the first one, the tail pointer changes to */if (list->size = = 1) {list->last = List->first;} Free (s); List->size--;return true;} /* Lookup function: Find the specified element: Returns a pointer to it, not found: Returns Null*/node *find_val (List *list,elemtype x) {Node *s = List->first->next;while (s! = List->first) {if (x = = S->data) return s;elses = S->next;} return NULL;} /* Delete nodes by value */bool delete_val (List *list,elemtype x) {Node *s = Find_val (list,x), if (s! = NULL) {/* Connection: Header Delete, tail delete, all applicable */s->pre- >next = S->next;s->next->pre = s->pre;/* release */free (s); list->size--;/* if the last node is released, the tail pointer needs to be changed to point, the rest does not need to change */if (s = = list->last) {list->last = S->pre;} return true;} else{cout<< "The item is not exist!" <<endl;return false;}} /*bool delete_val (List *list,elemtype x) {Node *s = Find_val (list,x); if (s = NULL) {if (s = = List->first->next) {Pop_ Front (list);} else if (s = = list->last)//Why not add else, delete the head node will be wrong??? {pop_back (list);} Else{s->pre->next = S->next;s->next->pre = S->pre;free (s); list->size--;} return true;} else{cout<< "The item is not exist!" <<endl;return false;}} *//* modifies the value specified in the list */bool modify (List *list,elemtype x) {Node *s = Find_val (list,x); Elemtype item;if (s! = NULL) {cout<< "Please input a new item:"; cin>>item;s->data = Item;return true;} else{cout<< "The item is not exist!" <<endl;return false;}} /* Empty the list */void clear (List *list) {node *s = list->first->next;//s always point to the first node in the list while (s! = List->first) {list-> First->next = s->next;//to empty the first node in the list free (s);//Release first nodes s = list->first->next;//re-points to the new first node}list->last = list->first;list->size = 0;} /* Destroy linked list */void destory (list *list) {clear (list); free (list->first); list->first = List->last = NULL;} /* List inverse: Keep the first node, leave the remaining nodes free, then head into the reserved node */void reverse (list *list) {node *s = list->first->next;//The first node node *p = s->next;//isolate the remaining nodes/* The first node is reversed and becomes the last node */s->next = List->first;list->last = S;while (P! = list->first) {s =      P Save Free the first node P = p->next;//for the next header insert/* will free out the first node---> Head plug-in */s->next = list->first->next;list- >first->next->pre = S;s->pre = List->first;list->first->next = S;/*Push_front (List,s->data); Free (s); Call the Push_front function, the node is created automatically, so you have to release the original node */}}/* the predecessor of the specified element */node *prio (List *list,elemtype x) {Node *s = Find_val (list,x ); if (s = NULL) {if (s = = List->first->next) {cout<< "It doesn ' t have prio!" <<endl;} Else{return S->pre;}} else{cout<< "The item is not exist!" <<endl;return NULL;}} /* For subsequent */node *next of the specified element (List *list,elemtype x{Node *s = Find_val (list,x); if (s = NULL) {if (s = = List->last) {cout<< "It doesn ' t have next!" <<endl;} Else{return S->next;}} else{cout<< "The item is not exist!" <<endl;return NULL;}} /* Insert by Value: If the inserted value already exists, return NULL, otherwise insert the value (assuming the linked list data is ordered: Ascending) */bool insert_val (List *list,elemtype x) {Node *s = Find_val (list,x); = NULL) {cout<< "The item is already exist!" <<endl;return false;} /* Create the node to insert */node *p = (node *) malloc (sizeof (node));p->data = x;/* Find the precursor to insert position */s = List->first;while (s! = list-> Last) {if (S->next->data > x) break;//to be inserted (inserted after s) elses = S->next;} /* Insert */p->next = S->next;s->next->pre = P;p->pre = S;s->next = p;/* To insert the position of the precursor is the last node, that is, the tail of the pointer needs to change the point */ if (s = = list->last) {list->last = P;} List->size++;return true;} /* Ascending */void sort (List *list) {node *s = list->first->next;//First node node *p = s->next;//Isolate the remaining nodes/* The first node is reversed and becomes the last node. */s->next = List->first;list->last = S;while (P! = list->first) {s = p;p = P->next/* * The first node that is freed is inserted by value into the Save node */insert_val (list,s->data); free (s);//Call Insert_val () creates a node, so the original node should be released}} 

Main.cpp:

#include "DCList.h" int main () {List mylist; Node *s;initlist (&mylist); Elemtype item;int choice = 1;while (choice) {Meau ();cout<< "Input You choice:" <<endl;cin>>choice; Switch (choice) {case 1:initlist (&mylist), break;case 2:cout<< "input the item you want to push_back:-1 as a end" &L T;<endl;while (Cin>>item,item! =-1) push_back (&mylist,item); break;case 3:cout<< "Input the item you Want to Push_back:-1 as a End "<<endl;while (cin>>item,item! =-1) push_front (&mylist,item); Break;case 4: Pop_back (&mylist); Break;case 5:pop_front (&mylist); break;case 6:cout<< "Input the item you want to find:" <<endl;cin>>item; Find_val (&mylist,item); if (Find_val (&mylist,item)! = NULL) cout<< "The item is found!" <<endl;elsecout<< "The item is not exist:" <<endl;break;case 7:show (&mylist); Break;case 8:cout << "Input the item want to modify:" <<endl;cin>>item;modify (&mylist,item);Case 9:cout<< "Input of the item want to delete:" <<endl;cin>>item;delete_val (&mylist,item); Break;case 10:clear (&mylist); Break;case 11:destory (&mylist); Break;case 12:reverse (&mylist); break;case 13:cout<< "Input the item want to find it ' s prio:" <<endl;cin>>item;s = Prio (&mylist,item); = NULL) cout<< "It ' s prio is:" <<s->data<<endl;break;case 14:cout<< "input the item you want to Find it's next: "<<endl;cin>>item;s = Next (&mylist,item);; if (s! = NULL) cout<< "It ' s Next is:" <<s->data<<endl;break;case 15:sort (&mylist); Break;case 16 :cout<< "Input the item want to insert:" <<endl;cin>>item;insert_val (&mylist,item); Default:break;}} Destory (&mylist); return 0;}

Specific functions: hope that the reader self-test, if there is a mistake welcome to propose amendments----->>>zyh_helen

(with head and tail pointers) the realization of various functions of cyclic doubly linked list