(Including the head pointer and tail pointer) implementation of various functions of the circular two-way linked list, pointer

(Including the head pointer and tail pointer) implementation of various functions of the circular two-way linked list, pointer

Implement the following functions for cyclic double-stranded tables:

Void meau (); // menu function void Initlist (List * list); // initialize void show (List * list); // print bool Push_back (List * list, elemType x); // bool Push_front (List * list, ElemType x); // bool Isempty (List * list ); // determine whether the linked List is empty bool Pop_back (list * List); // bool Pop_front (list * List) by means of tail deletion ); // Delete the Node * Find_val (List * list, ElemType x) by header; // query bool Delete_val (List * list, ElemType x) by value ); // Delete bool modify (List * list, ElemType x) by value; // modify void clear (List * list); // clear the void destory (List * list) of the linked List ); // destroy the linked List void reverse (list * List); // reverse the linked list Node * prio (List * list, ElemType x ); // Node * next (List * list, ElemType x) that is used to evaluate a value; // evaluate the successor bool Insert_val (List * list, ElemType x) of a value ); // 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 the content of the linked List bool Push_back (list * List, ElemType x); // insert bool Push_front (list * List, elemType x); // bool Isempty (List * list); // determines whether the linked List is empty bool Pop_back (list * List ); // bool Pop_front (List * list) by tail deletion; // Node * Find_val (List * list, ElemType x) by header deletion ); // search for bool Delete_val (List * list, ElemType x) by value; // Delete bool modify (List * list, ElemType x) by value ); // modify void clear (List * list); // clear the void destory (List * list); // destroy the linked table void reverse (List * list ); // reverse linked List Node * prio (list * List, ElemType x); // The Node * next (list * List, ElemType x) that is used to evaluate a value ); // find the successor bool Insert_val (List * list, ElemType x) of a value; // 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_back *" <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] p Rio * "<endl; cout <" * [14] next [15] sort * "<endl; cout <"* [16] Insert_val *" <endl;}/* initialize linked List */void Initlist (list * List) {Node * s = (Node *) malloc (sizeof (Node); assert (s! = NULL); s-> next = s-> pre = s; list-> first = list-> last = s; list-> size = 0 ;} /* tail plug method */bool Push_back (List * list, ElemType x) {Node * s = (Node *) malloc (sizeof (Node); 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 linked List content */void show (list * list) {Node * s = list-> first-> next; while (s! = List-> first) {cout <s-> data <"-->"; s = s-> next;} cout <"NULL" <endl ;} /* Header Insertion Method */bool Push_front (List * list, ElemType x) {Node * s = (Node *) malloc (sizeof (Node); if (s! = NULL) {s-> data = x;/* connects to the following elements (the original first element) */s-> next = list-> first-> next; list-> first-> next-> pre = s;/* connect to the header node */list-> first-> next = s; s-> pre = list-> first;/* if it is the first node, the tail Pointer Points to it */if (list-> size = 0) {list-> last = s;} list-> size ++; return true;} else {cout <"An error occurred while applying for a space! "<Endl; return false ;}/ * determines whether the linked List is empty */bool Isempty (list * list) {return (List-> size = 0 );} /* tail deletion method */bool Pop_back (List * list) {if (Isempty (list) {cout <"The linked List is empty! "<Endl; return false;} Node * s = list-> last-> pre; // find the precursor free (list-> last) of the last Node ); // release the last node/* connection */s-> next = list-> first; list-> last = s; list-> size --; return true ;} bool Pop_front (List * list) {if (Isempty (list) {cout <"The linked List is empty! "<Endl; return false;} Node * s = list-> first-> next; // locate the first Node (to be released) /* connect */list-> first-> next = s-> next; s-> next-> pre = list-> first; /* if the node to be deleted is the first node, the tail pointer must be changed to */if (list-> size = 1) {list-> last = list-> first;} free (s); list-> size --; return true;}/* search function: Find the specified element: returns the pointer to it. If not found, 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 deletion and tail deletion are applicable to */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, and the rest of the cases do not need to be changed */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 is an error occurred when deleting the header node if else is not added ??? {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 ;}} * // * modify the specified value in the linked 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 ;}/ * clear the linked List */void clear (list * list) {Node * s = List-> first-> next; // s always points to the first node in the linked list while (s! = List-> first) {list-> first-> next = s-> next; // empty the first node in the linked list for free (s ); // release the first node s = list-> first-> next; // point to the new first node again} list-> last = list-> first; list-> size = 0;}/* destroy linked List */void destory (list * list) {clear (list); free (list-> first ); list-> first = list-> last = NULL;}/* reverse linked list: retain the first node and remove the remaining nodes, then insert the headers to the reserved nodes in sequence */void reverse (List * list) {Node * s = list-> first-> next; // The first Node * p = s-> next; // separate the remaining Node/* The first Node is reversed and becomes the last Node */s-> n Ext = list-> first; list-> last = s; while (p! = List-> first) {s = p; // Save the first node freed from p = p-> next; // prepare for the next plug-in./* Insert the first node that is detached. ---> plug-in-> enter */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 to automatically create a node, so you have to release the original Node */}/* To find the precursor 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 ;}/ * Find the successor of the specified Element */Node * next (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, NULL is returned. Otherwise, the value is inserted (assuming that the Linked List data is sorted in ascending order) */bool Insert_val (List * list, ElemType x) {Node * s = Find_val (list, x); if (s! = NULL) {cout <"the item is already exist! "<Endl; return false;}/* Create the Node to be inserted */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; // locate the position to be inserted (insert after s) elses = s-> next;}/* Insert */p-> next = s-> next; s-> next-> pre = p; p-> pre = s; s-> next = p;/* if you want to insert the position, the first node is the last node, that is, the end node, the tail pointer needs to be changed to */if (s = list-> last) {list-> last = p;} list-> size ++; return true ;} /* ascending */void sort (List * list) {Node * s = list-> first-> next; // The first Node * p = s-> next; // separate 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;/* Insert the first node to the save node by value */Insert_val (list, s-> data); free (s); // call Insert_val () to create 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"<<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 you want to modify:"<<endl;cin>>item;modify(&mylist,item);break;case 9:cout<<"input the item you 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 you want to find it's prio:"<<endl;cin>>item;s = prio(&mylist,item);if(s != 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 you want to insert:"<<endl;cin>>item;Insert_val(&mylist,item);break;default:break;}}destory(&mylist);return 0;}

Specific functions: We hope you can test it by yourself. If you have any errors, please submit your suggestions for modification. -----> zyh_helen