数据结构——双循环链表一部分功能的C语言实现

#include <stdio.h>#include <malloc.h>#include <stdlib.h>typedef struct Node{    int data;    Node *next;    Node *last;}Node,*PNode;//节点 typedef struct List{    PNode head;    PNode tail;    int length;}List,*PList;//链表void initList(PList x){    PNode headNode=(PNode)malloc(sizeof(Node));    if(!headNode)        exit(0);    headNode->data=0;    headNode->next=headNode;    x->head=headNode;    x->tail=headNode;    x->length=0;}//初始化链表 int insertNode(PList x,int i,int e){    if(i>x->length)        return 1;    PNode newNode=(PNode)malloc(sizeof(Node));    if(!newNode)        exit(0);    newNode->data=e;    PNode p=x->head;    for(int j=0;j<i;j++)        p=p->next;    newNode->next=p->next;    p->next=newNode;    newNode->last=p;    newNode->next->last=newNode;    if(i==x->length)        x->tail=newNode;    x->length++;    return 0;}//插入结点 int deleteNode(PList x,int i){    if(i>x->length)        return 1;    PNode p=x->head;    for(int j=0;j<i-1;j++)        p=p->next;    PNode delNode=p->next;    p->next=delNode->next;    p->next->last=p;    if(i==x->length)        x->tail=p;    free(delNode);    x->length--;    return 0;}//删除结点 void outputList(PList x,int h_t=0){    if(h_t==0){        PNode p=x->head->next;        for(int i=0;i<x->length;i++){            printf("%3d",p->data);            p=p->next;        }        printf("\n");    }    else{        PNode p=x->tail;        for(int i=0;i<x->length;i++){            printf("%3d",p->data);            p=p->last;        }        printf("\n");    }}//打印链表，可选择从前往后或从后往前，默认为从前往后 int deleteList(PList x){    while(x->length>0){        deleteNode(x,x->length);        x->length--;    }    free(x->head);    x->head=NULL;    x->tail=NULL;}//删除链表  int main(){    //初始化链表     PList myList=(PList)malloc(sizeof(List));    initList(myList);    //添加节点    int e=0;    printf("请输入要添加的数据（10个）：");    for(int i=0;i<10;i++){        scanf("%d",&e);        insertNode(myList,myList->length,e);    }     outputList(myList,1);    //删除链表    deleteList(myList);     return 0;}