I was supposed to conver a singly linked list to a doubly linkedlist and everytime I run my program the output prints a bunch ofrandom numbers constantly until I close the console.

Here is the code.

#include
#include
#include
#include

struct node {
int data;

struct node *next;
struct node *prev;
};

//this always points to first link
struct node *head = NULL;

//this always points to last link
struct node *tail = NULL;

//return length of list
int sizeList (struct node *pointer)
{
int length = 0;
struct node *temp;

if(pointer == head)
{
for (temp = head; temp != NULL; temp = temp-> next)
length++;
}
else
{
for (temp = tail; temp != NULL; temp = temp-> prev)
length++;
}
return length;
}

//insert element from last node
struct Node* insertLast (struct node *tail, int newelement)
{
struct node *temp = (struct node*) malloc(sizeof(structnode));
temp-> data = newelement;

if (tail == NULL){
head = temp;
tail = temp;
}
else
{
tail-> next = temp;
temp-> prev = tail;
}
//point last to new last node
tail = temp;

return tail;
};

void printList(struct node *pointer)
{
int length = 0;
struct node *temp;

//check if pointer is head and print head of node
if (pointer == head)
{
for (temp = head; temp != NULL; temp = temp-> next)
printf(\"%d \", temp-> data);
}
//check if pointer is tail and print the list from tail node usingprevious pointer
else
{
for (temp = tail; temp != NULL; temp = temp-> prev)
printf(\"%d \", temp-> data);
}

printf(\"\n\");
}

int get (struct node *pointer, int position)
{
struct node *temp;
int length = sizeList(pointer);
int tempPosition = 0;

if (length < position)
{
printf(\"Enter the position with in %d.\", length);
return -1;
}
//check if pointer is head and return the element from theposition
if (pointer == head)
{
for (temp = head; temp != NULL; temp = temp-> next)
{
if(++tempPosition == position)
{
return temp-> data;
}
}
}
//check if pointer is tail and return the element from theposition
else
{
for (temp = tail; temp != NULL; temp = tail-> prev)
{
if (++tempPosition == position)
{
return temp-> data;
}
}
}
return 0;
}

//delete node from position
struct node* removeEle(struct node *head, int position)
{
struct node *temp = head, *deleteNode = NULL;
int i;

//traverse list until we get each position
for (i=1; i{
temp = temp-> next;
}

//if position is 1, move the head pointer to next and free nodeand return to head
if (position ==1)
{
deleteNode = temp;
temp = temp-> next;
temp-> prev = NULL;
head = temp;

free (deleteNode);
return head;
}

//if deleteNode is last position move the tail to previous nodeand free last node
else if (temp == tail)
{
deleteNode = tail;
tail = tail-> prev;
tail-> next = NULL;

free(deleteNode);
return head;
}
//swap temp pointers to skip node
else if (temp != NULL)
{
temp-> prev-> next = temp-> next;
temp-> next-> prev = temp-> prev;

free(temp); //delete n node
return head;
}
else
{
printf(\"It's an invalid position..\n\");
return head;
}
};

void reverseList(struct node *node)
{
//stop and return if node is null
if (!node)
return;

//swap next and prev pointer of node
struct node* temp = node-> next;
node-> next = node-> prev;
node-> prev = temp;

//node of prev is null stop and update head and tailpointer
if(!node-> prev)
{
head = node;
if(head-> next == NULL)
{
tail = head;
}
struct node *temp = head;
while(temp-> next != NULL)
{
temp = temp -> next;
}
tail = temp;
return;
}
//invoke recursive api
reverseList(node-> prev);
}

int main()
{
struct Node *tail = NULL;

//insert element at last
tail = insertLast(tail, 10);
tail = insertLast(tail, 20);
tail = insertLast(tail, 30);
tail = insertLast(tail, 40);
tail = insertLast(tail, 50);

printf(\"Printing from Head: \");
printList(head);
printf(\"\n\");

printf(\"Printing from Tail: \");
printList(tail);
printf(\"\n\");

printf(\"Size of list from Head: %d\n\", sizeList(head));
printf(\"Size of list from Tail: %d\n\", sizeList(tail));

//remove element from position 4
printf(\"Get the element from head at position 4: \");
int element = get(head, 4);

if(element != -1)
{
printf(\"%d\n\", element);
}

//remove element from position 2
printf(\"Get the element from tail at position 2: \");
element = get(tail, 2);

if(element != -1)
{
printf(\"%d\n\", element);
}

printf(\"Remove element from position 3\n\");
head = removeEle(head, 3);

printf(\"Printing from Head after removal: \");
printList(head);
printf(\"\n\");

//invoke reverse list
reverseList(head);

printf(\"Printing from Head after reverseList: \");
printList(head);
printf(\"\n\");

printf(\"Printing from tail after reverseList: \");
printList(tail);
printf(\"\n\");

return 0;
}