双向带头循环链表

头文件
#define _CRT_SECURE_NO_WARNINGS

#include<stdio.h>
#include<stdlib.h>
#include<assert.h>
#include<stdbool.h>

typedef int LTDataType;
typedef struct ListNode
{
LTDataType data;
struct ListNode* prev;
struct ListNode* next;
}LTNode;

LTNode* LTInit();
void LTDestroy(LTNode* phead);
void LTPrint(LTNode* phead);
bool LTEmpty(LTNode* phead);

void LTPushBack(LTNode* phead, LTDataType x);
void LTPopBack(LTNode* phead);

void LTPushFront(LTNode* phead, LTDataType x);
void LTPopFront(LTNode* phead);
//在pos位置之后插入数据
void LTInsert(LTNode* phead,LTNode* pos, LTDataType x);
void LTErase(LTNode* phead,LTNode* pos);
LTNode* LTFind(LTNode* phead, LTDataType x);

源文件

#define _CRT_SECURE_NO_WARNINGS#include"ListNode.h"LTNode* LTInit()
{LTNode*phead = (LTNode*)malloc(sizeof(LTNode));if (phead == NULL){printf("malloc失败！");exit(-1);}phead->next = phead;phead->prev = phead;phead->data = 0;return phead;
}
void LTDestroy(LTNode* phead)
{;
}
void LTPrint(LTNode* phead)
{LTNode* cur = phead->next;while (cur!=phead){printf("%d ", cur->data);cur = cur->next;}
}//尾插
void LTPushBack(LTNode* phead, LTDataType x)
{LTNode* newnode = (LTNode*)malloc(sizeof(LTNode));if (newnode == NULL){printf("malloc失败！");exit(-1);}newnode->data = x;newnode->next = phead;newnode->prev = phead->prev;phead->prev->next = newnode;phead->prev = newnode;
}
//尾删
void LTPopBack(LTNode* phead)
{assert(phead->next != phead);LTNode* tail = phead->prev;tail->prev->next = phead;phead->prev = tail->prev;free(tail);
}
//头插
void LTPushFront(LTNode* phead, LTDataType x)
{LTNode* newnode = (LTNode*)malloc(sizeof(LTNode));if (newnode == NULL){printf("malloc失败！");exit(-1);}LTNode* head = phead->next;newnode->data = x;newnode->next = head;newnode->prev = phead;phead->next = newnode;head->prev = newnode;
}
//头删
void LTPopFront(LTNode* phead)
{assert(phead->next != phead);LTNode* tmp = phead->next->next;phead->next = tmp;free(tmp->prev);tmp->prev = phead;
}
//在pos位置之后插入数据
void LTInsert(LTNode* phead,LTNode* pos, LTDataType x)
{LTNode* newnode = (LTNode*)malloc(sizeof(LTNode));if (newnode == NULL){printf("malloc失败！");exit(-1);}LTNode* tmp = pos->next;newnode->data = x;newnode->next = tmp;newnode->prev = pos;pos->next = newnode;tmp->prev = newnode;
}
void LTErase(LTNode* phead,LTNode* pos)
{assert(phead->next != phead);pos->prev->next = pos->next;pos->next->prev = pos->prev;free(pos);
}
bool LTEmpty(LTNode* phead)
{;
}
LTNode* LTFind(LTNode* phead, LTDataType x)
{LTNode* cur = phead->next;while (cur != phead){if (cur->data == x)return cur;cur = cur->next;}return NULL;
}