循环链表

循环链表，相对于普通单向链表，就是最后一个元素的指针域指向头结点

#include<bits/stdc++.h>
using namespace std;
#define sc scanf
#define pr printf

typedef struct LNode{
    int data;
    struct LNode *next;
}LNode,*LinkList; 

void Create_CircleList(LinkList &L,int n)
{
    LNode *p,*q;
    L = (LNode *)malloc(sizeof(LNode));
    L->data = 0;
    L->next = NULL;
    
    //创建最后一个结点 
    q = (LNode *)malloc(sizeof(LNode));
    scanf("%d",&q->data);
    q->next = L->next;
    L->next = q;
    
    for(int i = 1;i < n;i++)
    {
        p = (LNode *)malloc(sizeof(LNode));
        scanf("%d",&p->data);
        p->next = L->next;
        L->next = p;
    }
    //因为是循环链表，所以最后一个结点的指针指向头结点 
    q->next = L;
    
}

//遍历循环链表  
void Traver_CircleList(LinkList &L)
{
  LNode *p = L;
  while(p->next != L)
  {
       p = p->next;
     cout << p->data << " "; 
  }    
  puts("");
} 

int getLength(LinkList &L)
{
  LNode *p = L;
  int cnt = 0;
  while(p->next != L)
  {
       p = p->next;
     cnt++;
  }    
  return cnt;
}

//删除循环链表的某个结点
bool Delete_Node(LinkList &L,int i,int &e)
{
    int len = getLength(L);
    
    if(L->next == NULL)
    {
        puts("Sorry! Empty LinkList!");
        return 0;
    }
    if(i < 1 || i > len)
    {
        puts("Oh! Baby! The position is invalid. Please re-enter the position!");
        return 0;
    }
    LNode *p = L;
    int j = 0;
    while(p->next != L && j < i - 1)
    {
         p = p->next;
         j++;
    }    
    LNode *q;
    q = p->next;
    p->next = q->next;
    e = q->data;
    free(q);
    return 1;
} 

int main()
{
    LNode *la;
    int n,m;
    scanf("%d%d",&n,&m);
    Create_CircleList(la,n);
    
    cout << "La length = " << getLength (la) << endl;
    Traver_CircleList(la);
    int e;
    bool ok = Delete_Node(la,1,e);
    if(ok)
    {
        cout << "The delete number is " << e << endl;
        cout << "after delete La length = " << getLength(la) << endl;
        pr("after delete La is ");
        Traver_CircleList(la);
    }
    return 0;
}