题解 | #牛牛的链表添加节点#

#include <stdio.h>
#include <malloc.h>
typedef struct node
{
    int data;
    struct node *next;
}node;
//创建
node *creatnode()
{
    node *head=(node*)malloc(sizeof(node));
    if(head==NULL)
        return NULL;
    head->next=head;
    return head;
}
//尾插
void insertnode(node *head,int data)
{
    node *new=(node*)malloc(sizeof(node));
    if(head==NULL)
        return;
    new->data=data;
    new->next=NULL;
    node *p=NULL;
    for(p=head;p->next!=head;p=p->next);
    new->next=p->next;
    p->next=new;
}
void addnode(node *head,int i)
{
    int k;
    for(k=0;k<i;k++)
    {
        head=head->next;
    }
    node *p=(node*)malloc(sizeof(node));
    p->data=i;
    p->next=head->next;
    head->next=p;
}
//打印
void printfnode(node *head)
{
    if(head->next==head)
        return;
    node *p=head->next;
    while(p!=head)
    {
        //head=head->next;
        printf("%d ",p->data);
        p=p->next;
    }
}
int main()
{
    node *head=creatnode();
    int n,i;
    scanf("%d",&n);
    scanf("%d",&i);
    int a[n],k,j;
    for(k=0;k<n;k++)
    {
        scanf("%d",&a[k]);
    }
    for(j=0;j<n;j++)
    {
        insertnode(head, a[j]);
    }
    addnode(head, i);
    printfnode(head);
}