#include <stdio.h>
#include <conio.h>
#include <alloc.h>
#include <string.h>
struct cirlink {
  int x;
  struct cirlink *pre,*next;
} *ps1, *ps2;

void printp(struct cirlink *ps) { /* circle link list */
  struct cirlink *p;

  p=ps;
  printf("the input value is --> ");
  printf("%d ",p->x); p=p->next;
  while (p != ps) {
    printf("%d ",p->x);  p=p->next;
  }
  printf("\n");
}

struct cirlink * create() {
  char t[20];
  int x,n,cc,s,ff;
  struct cirlink *pp,*p,*ps;

  printf("give me the data --> "); gets(t); x=strlen(t); ff=0;
  printf("input string --> %s| length=%d\n",t,x);
  while (x > 4) {
    s=0; cc=4;
    while (cc >= 1) { s=s*10+(t[x-cc]-'0'); cc--; }
    if (s != 0) {
      if (ff == 0) {
	ff=1; ps=pp=p=(struct cirlink *)malloc(sizeof(struct cirlink));
	p->x=s; p->next=p->pre=p;
      }
      else {
	p=(struct cirlink *)malloc(sizeof(struct cirlink));
	p->x=s; p->pre=pp; p->next=ps; pp->next=p; pp=p; ps->pre=p;
      }
    }
    x-=4;
  }
  if (x > 0) {
    s=0; cc=x;
    while (cc >= 1) { s=s*10+(t[x-cc]-'0'); cc--; }
    if (s != 0) {
      p=(struct cirlink *)malloc(sizeof(struct cirlink));
      p->x=s; p->pre=pp; p->next=ps; pp->next=p; pp=p; ps->pre=p;
    }
  }
  return ps;
}

void main() {
  struct cirlink *p, *pnext;

  ps1=create();  printp(ps1);
  ps2=create();   printp(ps2);
}