约瑟夫环问题,用循环做

typedef struct node
{
int num,code;
struct node *next;
}lnode;
void main()
{
int i,j,key,n; /*i,j为记数器,key为输入的密码,n为人的总个数*/
lnode *p,*s,*head;
head=(lnode *)malloc(sizeof(lnode)); /*为头结点分配空间*/
p=head;
printf("Please enter the num of the person:"); /*输入人的总个数*/
scanf("%d",&n);
for(i=1;i<=n;i++)
{
printf("Person %d",i);
printf(" code: ");
scanf("%d",&key); /*输入各个人的密码*/
s=p;
p=(lnode *)malloc(sizeof(lnode)); /*创建新的结点*/
s->next=p;
p->num=i;
p->code=key;
}
p->next=head->next;
p=head;
head=head->next;
free(p);

p=head;
do
{
printf("\nPerson%d Code:%d",p->num,p->code); /*输出链表*/
p=p->next;
}while(p!=head);

printf("\nPlease enter your first key:"); /*输入第一个数*/
scanf("%d",&key);
do
{