linked list reverse c++ code example
Example 1: how to reverse a linked ist
class LinkedList {
static Node head;
static class Node {
int data;
Node next;
Node(int d)
{
data = d;
next = null;
}
}
Node reverse(Node node)
{
Node prev = null;
Node current = node;
Node next = null;
while (current != null) {
next = current.next;
current.next = prev;
prev = current;
current = next;
}
node = prev;
return node;
}
void printList(Node node)
{
while (node != null) {
System.out.print(node.data + " ");
node = node.next;
}
}
public static void main(String[] args)
{
LinkedList list = new LinkedList();
list.head = new Node(85);
list.head.next = new Node(15);
list.head.next.next = new Node(4);
list.head.next.next.next = new Node(20);
System.out.println("Given Linked list");
list.printList(head);
head = list.reverse(head);
System.out.println("");
System.out.println("Reversed linked list ");
list.printList(head);
}
}
Example 2: reverse a singly linked list in c
#include <stdio.h>
#include <stdlib.h>
struct node {
int data;
struct node *next;
}*head;
void createList(int n);
void reverseList();
void displayList();
int main()
{
int n, choice;
printf("Enter the total number of nodes: ");
scanf("%d", &n);
createList(n);
printf("\nData in the list \n");
displayList();
printf("\nPress 1 to reverse the order of singly linked list\n");
scanf("%d", &choice);
if(choice == 1)
{
reverseList();
}
printf("\nData in the list\n");
displayList();
return 0;
}
void createList(int n)
{
struct node *newNode, *temp;
int data, i;
if(n <= 0)
{
printf("List size must be greater than zero.\n");
return;
}
head = (struct node *)malloc(sizeof(struct node));
if(head == NULL)
{
printf("Unable to allocate memory.");
}
else
{
printf("Enter the data of node 1: ");
scanf("%d", &data);
head->data = data;
head->next = NULL;
temp = head;
for(i=2; i<=n; i++)
{
newNode = (struct node *)malloc(sizeof(struct node));
if(newNode == NULL)
{
printf("Unable to allocate memory.");
break;
}
else
{
printf("Enter the data of node %d: ", i);
scanf("%d", &data);
newNode->data = data;
newNode->next = NULL;
temp->next = newNode;
temp = temp->next;
}
}
printf("SINGLY LINKED LIST CREATED SUCCESSFULLY\n");
}
}
void reverseList()
{
struct node *prevNode, *curNode;
if(head != NULL)
{
prevNode = head;
curNode = head->next;
head = head->next;
prevNode->next = NULL;
while(head != NULL)
{
head = head->next;
curNode->next = prevNode;
prevNode = curNode;
curNode = head;
}
head = prevNode;
printf("SUCCESSFULLY REVERSED LIST\n");
}
}
void displayList()
{
struct node *temp;
if(head == NULL)
{
printf("List is empty.");
}
else
{
temp = head;
while(temp != NULL)
{
printf("Data = %d\n", temp->data);
temp = temp->next;
}
}
}