对单链表进行 删除、插入、排序 等操作。

#define FALSE  0
#define TRUE   1

typedef struct NODE{
 struct NODE *link;
 int value;
}NODE;

int length( NODE *head )
{
 NODE *current;
 int length = 0;
 current = head;

 while( current != NULL )
 {
  current = current->link;
  length++;
 }
 return length;
}

NODE *create()
{
 NODE *head, *p, *s;
 int value, cycle = 1;

 head = (NODE *)malloc( sizeof(NODE) );
 p = head;
 while( cycle )
 {
  printf( "/nPlease input the data:" );
  scanf( "%d", &value );
  if( value != 0 )
  {
   s = (NODE *)malloc( sizeof( NODE ) );
   s->value = value;
   printf("/n s->value = %d", s->value);
   p->link = s;
   p = s;
  }
  else
   cycle = 0;
 }
 head = head->link;
 p->link = NULL;
 return head;
}

void print( NODE *head )
{
 NODE *p = NULL;
 int n = 0;
 n = length( head );
 printf( "/n Now, These %d records are:/n", n );
 p = head;
 while( p != NULL )
 {
  printf("/n p->value %d", p->value);
  p = p->link;
 }
 printf("/n");
}

NODE *reserve( NODE *head )
{
 NODE *p1, *p2, *p3;
 printf("/nEntry reserve() ======= begin !!!!");
 if( head == NULL || head->link == NULL )
  return head;
 p1 = head;
 p2 = p1->link;
 while( p2 )
 {
  p3 = p2->link;
  p2->link = p1;
  p1 = p2;
  p2 = p3;
 }
 head->link = NULL;
 head = p1;
 printf("/nEntry reserve() ======= end   !!!!");
 return head;
}

int sll_insert( NODE **rootp, int new_value )
{
 register NODE *current;
 register NODE *_new;
 printf("/nEntry sll_insert() ======= begin !!!!");
 while( (current = *rootp) != NULL && current->value < new_value )
 {
  rootp = &current->link;
 }

 _new = (NODE *)malloc( sizeof(NODE) );
 if( _new == NULL )
  return FALSE;
 _new->value = new_value;

 _new->link = current;
 *rootp = _new;

 printf("/nEntry sll_insert() ======= end  !!!!");
 return TRUE;
}

NODE *del( NODE *head, int value )
{
 NODE *p1, *p2;
 p1 = head;
 printf("/nEntry del() ======= begin !!!!");
 while( p1->link != NULL && value != p1->value )
 {
  p2 = p1;
  p1 = p1->link;
 }

 if( value == p1->value )
 {
  if( p1 == head )
  {
   head = p1->link;
   free( p1 );  
  }
  else
  {
   p2->link = p1->link;
   free( p1 );
  }
 }
 else
 {
  printf( "/n %d is could not been found", value );
  return NULL;
 }
 printf("/nEntry del() ======= end   !!!!");
 return head;
}

NODE *sort( NODE *head )
{
 NODE *p;
 int temp;
 int n;
 int i, j;
 printf("/nEntry sort() ======= begin !!!!");
 n = length(head);

 if( head == NULL || head->link == NULL )
  return head;

 for( j = 1; j < n; j++ )
 {
  p = head;
  for( i = 0; i < n-j; i++ )
  {
   if( p->value > p->link->value )
   {
    temp = p->value;
    p->value = p->link->value;
    p->link->value = temp;
   }
   p = p->link;
  }
 }
 printf("/nEntry sort() ======= end   !!!!");
 return head;
}

int main(void)
{
 NODE *head = NULL;
 NODE *_new = NULL;
 NODE *returnp = NULL;
 NODE *delp = NULL;
 NODE *sortp = NULL;
 int length = 0;
 head = create();
 print( head );
 _new = reserve( head );
 print(_new);
 sll_insert( &_new, 100);
 print( _new );
 delp = del( _new, 4 );
 print( delp );
 sortp = sort(delp);
 print( sortp );
 return 0;
}