自我学习之双向链表

#include "stdlib.h"#include <sys/types.h>//节点typedefstruct ListNode{int data;//数据struct ListNode* prev;//前指针struct ListNode* next;//后指针}LIST_NODE;//链表typedef struct list{LIST_NODE* head; //头指针LIST_NODE* tail; //尾指针LIST_NODE* frwd; //正向迭代指针LIST_NODE* bkwd; //反向迭代指针}LIST;//创建节点static LIST_NODE* create_node(int data,LIST_NODE* prev,LIST_NODE* next){LIST_NODE* node =(LIST_NODE*)malloc(sizeof(LIST_NODE));node->data=data;node->prev=prev;node->next=next;return node;}//销毁节点static LIST_NODE* destroy_node(LIST_NODE* node,LIST_NODE** prev){LIST_NODE* next = node->next;if (prev){*prev=node->prev;}free(node);return next;}//初始化void list_init(LIST* list){list->head=NULL;list->tail=NULL;}//释放所有节点void list_deinit(LIST* list){while(list->head)list->head = destroy_node(list->head,NULL);list->tail = NULL;}//判断是否为空int list_empty(LIST* list){return !list->head && !list->tail;}//后插void list_append(LIST* list,int data){list->tail=create_node(data,list->tail,NULL);if (list->tail->prev){list->tail->prev->next=list->tail;}else list->head=list->tail;}//前插void list_apphead(LIST* list,int data){list->head=create_node(data,NULL,list->head);if (list->head->next){list->head->next->prev=list->head;}elselist->tail=list->head;}//随机插void list_insert(LIST* list,size_t pos,int data){LIST_NODE* find =NULL;for (find=list->head;find;find=find->next){if (!pos--){LIST_NODE* node =create_node(data,find->prev,find);if (node->prev){node->prev->next=node;}elselist->head=node;node->next->prev=node;break;}}}//随机访问int* list_at(LIST*list,size_t pos){LIST_NODE*find =NULL;for (find=list->head;find;find=find->next){if (!pos--){break;}}return &find->data;}//删除void list_erase(LIST*list,size_t pos){LIST_NODE* find=NULL;for (find=list->head;find;find->next){if (!pos--){LIST_NODE* prev=NULL;LIST_NODE* next=destroy_node(find,&prev);if (prev){prev->next=next;}elselist->head=next;if (next){next->prev=prev;}elselist->tail=prev;break;}}}//删除匹配到的数据void list_remove(LIST* list,int data){LIST_NODE* find=NULL,*next =NULL;for(find=list->head;find;find=next){next=find->next;if (find->data==data){LIST_NODE* prev=NULL;LIST_NODE* next=destroy_node(find,&prev);if (prev){prev->next=next;}elselist->head=next;if (next){next->prev=prev;}elselist->tail=prev;}}}//数量size_t list_size(LIST*list){size_t size=0;LIST_NODE* node;for (node=list->head;node;node=node->next){++size;}return size;}//开始正向迭代void list_begin(LIST* list){list->frwd=list->head;}//继续正向迭代int* list_next(LIST* list){int* pdata = &list->frwd->data;list->frwd=list->frwd->next;return pdata;}//获取正向迭代int* list_current(LIST* list){return &list->frwd->data;}//终止正向迭代void list_end(LIST* list){list->frwd=list->tail->next;}//判断正向迭代是否终止int list_done(LIST* list){return list->frwd == list->tail->next;}//开始反向迭代void list_rbegin(LIST* list){list->bkwd=list->tail;}//继续反向迭代int* list_rnext(LIST* list){int* pdata = &list->bkwd->data;list->bkwd=list->bkwd->prev;return pdata;}//获取反向迭代int* list_rcurrent(LIST* list){return &list->bkwd->data;}//终止反向迭代void list_rend(LIST* list){list->bkwd=list->head->prev;}//判断反向迭代是否终止int list_rdone(LIST* list){return list->bkwd == list->head->prev;}