雙鏈表是用最快的時間實現鏈表的一種方式，具體的實現代碼如下：

#pragma once
#include<stdio.h>
#include<stdlib.h>
#include<assert.h>typedef int LTDataType;
typedef struct ListNode
{LTDataType data;struct ListNode* next;//下一個節點struct ListNode* prev;//上一個節點
}LTNode;//初始化
LTNode* LTInit();
//銷毀
void LTDestroy(LTNode* phead);
//打印
void LTPrint(LTNode* phead);
//bool LTEmpty(LTNode* phead);
//尾插
void LTPushBack(LTNode* phead, LTDataType x);
//尾刪
void LTPopBack(LTNode* phead);
//頭插
void LTPushFront(LTNode* phead, LTDataType x);
//頭刪
void LTPopFront(LTNode* phead);

#include"dlist.h"
//創建新節點
LTNode* CreateLTNode(LTDataType x)
{LTNode* newnode = (LTNode*)malloc(sizeof(LTNode));if (newnode == NULL){perror("malloc fail");exit(-1);}newnode->data = x;newnode->next = NULL;newnode->prev = NULL;return newnode;
}
//初始化
LTNode* LTInit()
{LTNode* phead = CreateLTNode(-1);phead->next = phead;phead->prev = phead;return phead;
}
//銷毀
void LTDestroy(LTNode* phead)
{assert(phead);LTNode* cur = phead->next;while (cur != phead){LTNode* next = cur->next;free(cur);cur = next;}free(phead);phead = NULL;
}
//打印
void LTPrint(LTNode* phead)
{assert(phead);LTNode* cur = phead->next;while (cur != phead){printf("%d<=>", cur->data);cur = cur->next;}printf("NULL\n");
}
//尾插
void LTPushBack(LTNode* phead, LTDataType x)
{LTNode* newnode = CreateLTNode(x);LTNode* tail = phead->prev;newnode->prev = tail;newnode->next = phead;tail->next = newnode;phead->prev = newnode;
}
//尾刪
void LTPopBack(LTNode* phead)
{assert(phead);LTNode* tail = phead->prev;tail->prev->next = phead;phead->prev = tail->prev;free(tail);tail = NULL;
}
//頭插
void LTPushFront(LTNode* phead, LTDataType x)
{assert(phead);LTNode* newnode = CreateLTNode(x);LTNode* next = phead->next;phead->next = newnode;newnode->prev = phead;newnode->next = next;next->prev = newnode;
}
//頭刪
void LTPopFront(LTNode* phead)
{assert(phead);LTNode* cur = phead->next;phead->next = cur->next;cur->next->prev = phead;free(cur);cur = NULL;
}

在初始化的過程中，因為要改變phead的值，所以要傳入二級指針?，但是為了保證統一，只需要初始化的時候返回一個節點指針就可以避免傳入二級指針