Question

Question 3: Reversing a singly-linked list of integers Suppose that you have a singly-linked list detined via the following data type (30) Integet itemt net: et stem in 1ist Complete the following function so that it reverses the list pointed to by the arguwent void reverse linkedlist(list itom tx shead)

Answer 1

#include <iostream>

using namespace std;

//Struct for node
typedef struct list_item_t
{
int data;
list_item_t *next;
} list_item_t ;

list_item_t *head;

void add(int x)
{
list_item_t *newNode = new list_item_t();
newNode->data = x;
newNode->next = NULL;

if(head==NULL)
{
head = newNode;
return;
}
list_item_t *temp = head;
while(temp->next!=NULL)
{
temp = temp->next;
}
temp->next = newNode;
}

void display()
{
list_item_t *temp = head;
while(temp!=NULL)
{
cout<<temp->data<<"->";
temp = temp->next;
}
cout<<"NULL"<<endl;
}

void reverse_linked_list(list_item_t *node){
//Make this node as prev
list_item_t *prev = node;
//Make next node as current
list_item_t *current = prev->next;
//Set previous node of first node to null
prev->next = NULL;
//Loop through the list
while(current!=NULL){
//Store next node of current node
list_item_t *nextnext = current->next;
//Mark current node's next to previous node
current->next = prev;
//Make current node previous node
prev = current;
//Update the currentNode to next node
current = nextnext;
}
//Finally change the head
head = prev;
}

int main()
{
add(2);
add(3);
add(4);
add(5);
display();
reverse_linked_list(head);
cout<<"After reversing the linked list "<<endl;
display();
// int p = prod(head);
//cout<<"Product is "<<p<<endl;
return 0;
}

OUTPUT :