建立一个带头结点的单向链表，链表中的各结点按结点数据中的数据递增有序链接，函数fun的功能是：把形参x的值放入一个新结点并插入链表中，使插入后各结点数据域中的数据仍保持递增有序

#include    <stdio.h>
#include    <stdlib.h>
#define    N    8
typedef  struct list
{  int  data;
   struct list  *next;
} SLIST;
void fun( SLIST  *h, int  x)
{  SLIST  *p, *q, *s;
   s=(SLIST *)malloc(sizeof(SLIST));
/**********found**********/
   s->data=x;将形参x赋给结点的数据域
   q=h;
   p=h->next;
   while(p!=NULL && x>p->data) {
/**********found**********/
      q=p;
      p=p->next;
   }
   s->next=p;
/**********found**********/
   q->next=s;
}
SLIST *creatlist(int  *a)
{  SLIST  *h,*p,*q;      int  i;
   h=p=(SLIST *)malloc(sizeof(SLIST));
   for(i=0; i<N; i++)
   {  q=(SLIST *)malloc(sizeof(SLIST));
      q->data=a[i];  p->next=q;  p=q;
   }
   p->next=0;
   return  h;
}
void outlist(SLIST  *h)
{  SLIST  *p;
   p=h->next;
   if (p==NULL)  printf("\nThe list is NULL!\n");
   else
   {   printf("\nHead");
       do { printf("->%d",p->data);  p=p->next;  } while(p!=NULL);
       printf("->End\n");
   }
}
main()
{  SLIST  *head;      int  x;
   int  a[N]={11,12,15,18,19,22,25,29};
   head=creatlist(a);
   printf("\nThe list before inserting:\n");  outlist(head);
   printf("\nEnter a number :  ");  scanf("%d",&x);
   fun(head,x);
   printf("\nThe list after inserting:\n");  outlist(head);
}