C. Create, output, delete, and insert a Dynamic Linked List

Dynamic Linked List creation, output, deletion, and insertion

# Include <stdio. h>

# Include <malloc. h>

# Include <stdlib. h>

# Define null 0

# Define Len sizeof (struct student)

Struct student

{

Long num;

Float score;

Struct student * next;

};

Int N;/* n is the global variable */

 

Struct student * creat ()

{

Struct student * P1, * P2, * head;

N = 0;

P1 = P2 = (structstudent *) malloc (LEN );

Scanf ("% lD, % F", & P1-> num, & P1-> score );

Head = NULL;

While (P1-> num! = 0)

{

N = n + 1;

If (n = 1)

Head = p1;

Elsep2-> next = p1;

P2 = p1;

P1 = (structstudent *) malloc (LEN );

Scanf ("% lD, % F", & P1-> num, & P1-> score );

}

P2-> next = NULL;

Return (head );

}

 

 

Void print (struct student * head)

{

Struct student * P;

Printf ("\ nthese records are: \ n ");

P = head;

If (Head! = NULL)

Do

{

Printf ("% lD, % F \ n", p-> num, p-> score );

P = p-> next;

} While (P! = NULL );

}

 

 

Struct student * del (struct student * head, long num)

{

Struct student * P1, * P2;

 

If (Head = NULL)

{Printf ("\ NLIST null! \ N "); goto end ;}

 

P1 = head;

While (num! = P1-> num & P1-> next! = NULL)

{

P2 = p1; P1 = p1-> next;

}

If (num = p1-> num)

{

If (p1 = head) Head = p1-> next;

Else P2-> next = p1-> next;

Printf ("delete: % LD \ n", num );

N = n-1;

}

Else printf ("% d not beenfound! \ N ", num );

End :;

Return (head );

}

 

Struct student * insert (struct student * head, struct student * stud)

{

Struct student * P0, * P1, * P2;

P1 = head;

P0 = stud;

If (Head = NULL)

{

Head = P0; P0-> next = NULL;

}

Else

{

While (P0-> num> P1-> num) & (P1-> next! = NULL ))

{

P2 = p1;

P1 = p1-> next;

}

 

If (P0-> num <= p1-> num) // conflicts with the preceding if, incorrect

{

If (Head = p1) Head = P0;

Else P2-> next = P0;

P0-> next = p1;

}

Else

{P1-> next = P0; P0-> next = NULL ;}

}

N = n + 1;

Return (head );

}

 

Void main ()

{

Struct student * head, Stu;

Long del_num;

Printf ("inputrecords: \ n ");

Head = creat ();

Print (head );

 

Printf ("\ ninputthe deleted number :");

Scanf ("% lD", & del_num );

Head = del (Head, del_num );

Print (head );

 

Printf ("\ ninputthe inserted record :");

Scanf ("% d, % F", & Stu. Num, & Stu. Score );

Head = insert (Head, & Stu );

Print (head );

}