#include  "datastru.h"
#include  <stdio.h>
#include  <malloc.h>

void delete(LINKLIST *a){
/*在有序鏈表中刪除重復(fù)元素,保留一個(gè)*/
LINKLIST *la;

la = a->next;
while(la != NULL && la->next != NULL)
 if (la->data == la->next->data)
    la->next = la->next->next;
 else la = la->next;
}

int count_head(LINKLIST *head){
/*帶頭結(jié)點(diǎn)的單鏈表:輸出單鏈表元素值并計(jì)數(shù)*/
  int i = 0;
  LINKLIST *p;
  p = head->next;
  printf("輸出單鏈表元素值 : ");
  while(p != NULL)
   {i++;
    printf("  %c",p->data);
    p = p->next;}
    printf("\n\n");
    return i;
}

LINKLIST *creatlink_order_head(LINKLIST *head)
/*建立帶頭結(jié)點(diǎn)的有序單鏈表*/
{ LINKLIST *t, *p, *q;
  char ch;

  t = (LINKLIST *)malloc(sizeof(LINKLIST));
  head = t;  t->next = NULL;
  printf("單鏈表元素值為單個(gè)字符, 連續(xù)輸入，$為結(jié)束字符  : ");
  while ((ch = getchar()) != '$')
   {t = (LINKLIST *)malloc(sizeof(LINKLIST));
    t->data = ch;
    q = head;  p = head->next;
    while( p != NULL && p->data <= ch) {
	q = p;  p = p->next;}
    q->next = t; t->next = p;
   }
  return(head);
}

main()
{
  LINKLIST *head = NULL;
  int  num;
  
  printf("\n    建立單鏈表\n\n");
  head = creatlink_order_head(head);
  fflush(stdin);
  num = count_head(head);
  printf("\n    刪除重復(fù)元素后\n\n");
  delete(head);
  num = count_head(head);
}