双向循环链表

双向循环链表

#include <stdio.h>

typedef struct DuLNode{
int data;
struct DuLNode *prior, *next;
}DuLNode;

DuLNode* createNullList();         /**创建空链表的函数的声明**/
int isNullList(DuLNode*);      /**判断是否链表是否为空的函数的声明(Y-1,N-0)**/
int insertNode(DuLNode*, int, int); /**在双向链表某位置插入结点的函数的声明**/
int delNode(DuLNode*, int, int*); /**删除双向链表某位置插入结点的函数的声明**/
void print_L(DuLNode*);
void print_hyphen(int);

int main(void)
{
DuLNode *head;
head = createNullList();
if(head == NULL){
printf("链表初始化失败！\n");
exit(1);
}
printf("链表初始化成功！\n");
int end = 0;
int ope;
while(!end){
print_hyphen(15); printf("\n");
printf("请输入指令来执行操作\n");
print_hyphen(15); printf("\n");
printf("1、判断双向循环链表是否为空\n2、在链表某位置插入新结点\n3、删除链表某位置的结点\n4、退出\n");
print_hyphen(15); printf("\n");
printf("输入要使用的功能的序号: ");
scanf("%d", &ope);
switch(ope){
case 1:
if(isNullList(head))       /**判断是否链表是否为空的函数的调用(Y-1,N-0)**/
printf("链表为空!\n");
else
printf("链表不为空!\n");
break;

case 2:{
int inset, insnum;
printf("请输入要插入到链表的数据的位置： ");
scanf("%d", &inset);
printf("请输入要插入的数据： ");
scanf("%d", &insnum);
if(insertNode(head, inset, insnum))
printf("插入成功！\n");
else
printf("插入失败！\n");
print_L(head);
break;
}

case 3:{
int delset, delnum;
printf("请输入要删除的结点的位置： ");
scanf("%d", &delset);
if(delNode(head, delset, &delnum)){
printf("删除成功！删除的数据为：%d\n", delnum);
}
else
printf("删除失败！\n");
print_L(head);
break;
}

case 4:
printf("再见！\n");
end = 1;
break;

default:
printf("无此序号，请重新输入！\n");
}
}
return 0;
}

DuLNode* createNullList()         /**创建空双向循环链表的函数的定义**/
{
DuLNode* head = NULL;
head=(DuLNode*)malloc(sizeof(DuLNode));
if(head!=NULL){
head->prior = head->next = head;
printf("Has create null list success!\n");
}
else
printf("Out of space!\n");
return head;
}

int isNullList(DuLNode *head)      /**判断双向循环链表是否为空的函数的定义(Y-1,N-0)**/
{
return (head->prior == head && head->next == head);
}

int insertNode(DuLNode *head, int set, int n)    /**在某位置插入结点的函数的定义**/
{
DuLNode *pnew = (DuLNode*)malloc(sizeof(DuLNode));
if(pnew == NULL){
printf("Out of space!\n");
return 0;
}
DuLNode *p;
p = head;
while(set--)
p = p->next;
p = p->prior;
pnew->data = n;
pnew->next = p->next;
pnew->prior = p;
p->next->prior = pnew;
p->next = pnew;
return 1;
}

int delNode(DuLNode *head, int set, int *n)  /**删除某位置的结点的函数的定义**/
{
DuLNode *p = head, *pdel;
while(set--)
p = p->next;
pdel = p;
*n = pdel->data;
p = pdel->prior;
pdel->next->prior = p;
p->next = pdel->next;
free(pdel);
return 1;
}

void print_L(DuLNode *head)
{
printf("\n当前链表中的数据为:\n");
DuLNode *p = head->next;
while(p != head){
printf("%d ", p->data);
p = p->next;
}
printf("\n");
}

void print_hyphen(int n)
{
while(n--)
printf("-");
}