Recursive/non-Recursive Algorithms in reverse order of linked lists

C code
/**
* Recursive/non-recursive algorithms of the Reverse Sequence of the linked list
*/
# Include <stdio. h>
Typedef int Item;
Typedef struct node
{
Item item;
Struct node * next;
} Node, * List;
 
/* Reverse1 ~ 2 is a reverse algorithm without leading nodes */
List reverse1 (List l)
{
Node * p1, * p2;
If (l = NULL)
Return l;
P1 = l-> next;
L-> next = NULL;
While (p1! = NULL ){
P2 = p1-> next;
P1-> next = l;
 
L = p1;
P1 = p2;
}
Return l;
}
List reverse2 (List l)
{
If (l = NULL | l-> next = NULL)
Return l;
Node * p = reverse2 (l-> next );
L-> next = l;
L-> next = NULL;
Return p;
}
/* Reverse3 ~ 4 is the reverse algorithm of the linked list of leading nodes */
Void reverse3 (List l)
{
Node * p1, * p2, * p3;
If (l = NULL | l-> next = NULL)
Return;
P1 = l-> next;
P2 = p1-> next;
P1-> next = NULL;
While (p2! = NULL ){
P3 = p2-> next;
P2-> next = p1;
P1 = p2;
P2 = p3;
}
L-> next = p1;
}
Void reverse4 (List l, Node * first)/* this algorithm is not very good. You need to Judge l outside the function! = NULL */
{
If (first = NULL | first-> next = NULL ){
L-> next = first;
Return;
}
Reverse4 (l, first-> next );
First-> next = first;
First-> next = NULL;
}

Author "Ackerman's Blog"