循環雙連結清單的頭插尾插等操作

“DLinkList.h”

#include<stdio.h>
#include<stdlib.h>
typedef char DLinkType;

typedef struct DLinkNode {
    DLinkType data;
    struct DLinkNode* next;
    struct DLinkNode* prev;
} DLinkNode, DLinkList;
DLinkNode* CreateNode(DLinkType value);
void DLinkListInit(DLinkNode** head);
void DLinkListPushBack(DLinkNode** head, DLinkType value);
void print(DLinkNode* head);
void DLinListPopBack(DLinkNode* head);
void DLinkListPushFront(DLinkNode* head, DLinkType value);
void DLinkListPopFront(DLinkNode* head);
void DLinkListInsert(DLinkNode* head, DLinkNode* pos, DLinkType value);
           

DLinkList.cpp

#include"DLinkList.h"
DLinkNode* CreateNode(DLinkType value)
{
    DLinkNode *new_Node = (DLinkNode*)malloc(sizeof(DLinkNode));
    new_Node->data = value;
    new_Node->next = NULL;
    new_Node->prev = NULL;
    return new_Node;
}
void DLinkListInit(DLinkNode** head)
{
    DLinkNode* newnode = CreateNode();
    if (head == NULL)
        return;
    *head = newnode;
    (*head)->next = *head ;
    (*head)->prev = *head;
}

void DLinkListPushBack(DLinkNode** head, DLinkType value)
{
    if (head == NULL)
        return;
    DLinkNode* cur = *head;
    DLinkNode* newnode = CreateNode(value);
    if ((*head) == NULL)
        cur = newnode;
    else
    {
        while (cur->next != *head)
            cur = cur->next;
        cur->next = newnode;
        newnode->prev = cur;
        newnode->next = *head;
        (*head)->prev = newnode;
    }
}
void print(DLinkNode* head)
{
    if (head == NULL)
        return;
    DLinkNode* cur = head->next;
    if (cur == head)
        return;
    else
    {
        while (cur != head)
        {
            printf("%c ", cur->data);
            cur = cur->next;
        }
    }
}
void DLinListPopBack(DLinkNode* head)
{
    DLinkNode* cur = head->next;
    DLinkNode* to_delete;
    if (head == NULL)
        return;
    else
    {
        if (cur == head)
        {
            cur->next = head;
            head->prev = cur;
        }
        else
        {
            while (cur->next != head)
                cur = cur->next;
            to_delete = cur;
            cur->next->prev = cur->prev;
            cur->prev->next = cur->next;
            free(to_delete);
        }
    }
}
void DLinkListPushFront(DLinkNode* head, DLinkType value)
{
    DLinkNode* cur = head->next;
    DLinkNode* newnode = CreateNode(value);
    if (cur == NULL)
    {
        cur = newnode;
    }
    else
    {
        newnode->next = head->next;
        newnode->prev=head->next->prev;
        head->next = newnode;
        newnode->prev = head;

    }
}
void DLinkListPopFront(DLinkNode* head)
{
    if (head == NULL)
        return;
    DLinkNode* cur = head->next;
    DLinkNode* to_delete;
    if (cur == head)
        return;
    else
    {
        if (cur == head)
        {
            cur->next = head;
            head->next = cur;
            free(head);
        }
        else
        {
            to_delete = cur;
            head->next=cur->next;
            cur->next->prev = head;
            free(to_delete);
        }
    }
}
void DLinkListInsert(DLinkNode* head,DLinkNode* pos, DLinkType value)
{
    if (head == NULL&&pos == NULL)
        return;
    DLinkNode* cur = head->next;
    DLinkNode* newnode = CreateNode(value);
    if (cur->next == head)
    {
        if (cur->next == pos)
        {
            head->next = newnode;
            newnode->prev = head;
            newnode->next = cur;
            cur->prev = newnode;
        }
        else
        {
            return;
        }
    }
    else
    {
        while (cur != pos)
            cur = cur->next;
        if (cur != head)
        {
            newnode->next = cur->next;
            newnode->prev = cur->next->prev;
            cur->next = newnode;
            newnode->prev = cur;
        }
        else
            return;

    }
}
           

text.cpp

#include"DLinkList.h"
int main()
{
    DLinkList *L;
    DLinkListInit(&L);
    DLinkListPushBack(&L, '9');
    DLinkListPushBack(&L, '5');
    DLinkListPushBack(&L, '+');
    DLinListPopBack(L);
    DLinkListPushFront(L, '5');
    DLinkListPopFront(L);
    DLinkListPopFront(L);
    DLinkListPopFront(L);
    DLinkListPopFront(L);
    DLinkListInsert(L, L, '1');
    print(L);
    system("pause");
    return 0;
}