C语言链表的实验有问题 作者:xieaotian发表于2010-02-02 14:39:05
该段代码调试了N次，还是存在问题，不知道该怎么改了。
/*编写一个建立考生链表的函数 creat() .每个考生的数据包括准考证号
(8字符) 姓名(16字符) 总分三个部分*/
#include
#include
#include
#define NULL 0
struct student
{
char Num[9];
char Name[16];
int score ;
struct student *next;
};
struct student *creat( )
{
struct student *head , *tail , *New ;
char Num[9];
char Name[16];
int score;
int size = sizeof ( struct student );
head = tail = NULL ;
printf ( "please input the first DATA : \n Number Name Score \n");
scanf ( " %s ", Num );
scanf ( " %s ", Name );
scanf ( " %d ", &score );
while ( score != 0 )
{
New = ( struct student *)malloc ( size ); // 为新结点开辟内存空间
strcpy ( New -> Num , Num );
strcpy ( New -> Name, Name );
New -> score = score ;
New -> next = NULL ;
if ( head == NULL )
head =New ;
else
tail -> next = New ;
tail =New;
printf ( "Please input the next DATA : \n Number Name Score \n");
scanf ( " %s " ,Num );
scanf ( " %s " ,Name );
scanf ( " %d" ,&score );
}
return head ;
}
/*编写一个输出考生链表的函数 print () */
void print ( struct student *head )
{
struct student *p = head ;
printf ( "Number Name Score \n");
while ( p != NULL )
{
printf ( " %s " , p -> Num );
printf ( " %s " , p -> Name );
printf ( " %d ", p -> score );
printf ( "\n" ) ;
p = p -> next ;
}
}
/*调用1， 2 两个函数， 并对其验证正确性
void main ()
{
struct student *head ;
head = creat ( ) ;
print ( head ) ;
} */
/*编写一个函数belongTo（） 函数，它负责检查一个指定的准考正号
是否已经存在链表中 ，如果已经存在，则返回在第几个节点，否则
返回0 */
int belongTo ( char Num[] )
{
struct student *p , *head ;
int count = 0 ;
p = head ;
while ( p && strcmp ( p -> Num ,Num))
{
p = p -> next ;
count++;
}
if ( !p )
return 0;
return count;
}
/*第5题 */
struct student *insert ( struct student *head )
{
struct student *p1 ,*min ,*p2 ,*New ;
char Num[9];
int size = sizeof ( struct student );
p1 = head ;
strcpy ( min -> Num , p1 -> Num );
p1 = p1 -> next ;
while ( p1 -> next )
{
if ( strcmp ( min -> Num , p1 -> Num ) > 0 )
{
strcpy ( p2-> Num , min -> Num );
strcpy ( min -> Num , p1 -> Num );
strcpy ( p1 -> Num , min -> Num ) ;
}
p1 = p1 -> next ;
}
printf ( " please input a new data : \n " );
scanf ( " %s " ,&Num ) ;
New = ( struct student * ) malloc ( size ) ;
p1 = head ;
strcpy ( New -> Num , Num );
while ( p1 -> next )
{
if ( belongTo ( p1 -> Num ) != 0 )
{
printf (" This number is not existed ,please reinput :\n ");
scanf ( " %s " ,&Num );
strcpy ( p1 -> Num , Num );
}
p1 = p1 -> next ;
}
p1 = head ;
if ( head == NULL )
{
head = New ;
New -> next = NULL ;
}
else
{
while ( (p1 -> next) && ( New -> Num > p1 -> Num ) )
{
p2 = p1 ;
p1 = p1 -> next ;
}
if ( New -> Num <= p1 -> Num )
{
if ( head == p1 )
head = New ;
else
p2 -> next = New ;
New -> next = p1 ;
}
else
{
p1 -> next = New ;
New -> next = NULL ;
}
}
return head ;
}
/*NO.6 */
struct student *Delete ( struct student *head )
{
struct student *p1 ,*p2 ,*p3;
char Num[9];
if ( head == NULL)
{
printf ( "\nlist null");
return head;
}
p1 = head ;
printf ("please input a number : \n");
scanf ( "%s" , Num);
if ( belongTo ( Num ) == 0)
{
printf ( "This number is not existed ,please reinput \n");
scanf ( "%s" , Num);
} //利用belongto函数进行检查
while ( strcmp ( p1 -> Num ,Num) && ( p1 -> next))
{
p2 = p1 ;
p1 = p1 -> next ;
}
if ( strcmp ( p1 -> Num ,Num) == 0) //find the site
{
if ( head == p1 )
head = p1 -> next ;
else
p2 -> next = p1 -> next ;
printf ( "Delete : %s \n" , Num);
free ( p1 );
}
return head ;
}
/*NO.7 */
void main ()
{
struct student *head;
int Num ,i ;
head = creat ( );
for ( i = 0 ; i < 35 ; i++ ) // to make the print beautiful
printf ("*");
printf ("\n");
printf ( " 0 : Exit \n ");
printf ( " 1 : Insert \n ");
printf ( " 2 : Delete \n ");
printf ( " 3 : Display \n ");
printf ( "Please input your choice ;\n ");
scanf ( "%d", Num );
printf ( "\n" );
for ( i = 0 ; i < 35 ; i++ )
printf ("*");
switch ( Num )
{
case 0 : exit ( 0 );
break;
case 1 : insert ( head );
break;
case 2 : Delete ( head );
break;
case 3 : print ( head );
break;
}
}