JAVA this function reverses the linked list Examples thi

JAVA

/**

   * this function reverses the linked list

   *

   * Examples: this : null ==> resulting this : null this : 2 --> null ==>

   * resulting this : 2 --> null this : -5 --> 5 --> -4 --> null ==> resulting

   * this : -4 --> 5 --> -5 --> null this : 1 --> 3 --> 5 --> null ==>

   * resulting this : 5 --> 3 --> 1 --> null

   */

Function name:

   public void reverse() {

       // TODO

Solution

package reversealinkedlist;

import java.io.*;

/**
*
* @author Ramesh
*/
public class ReverseALinkedList{

//This class represents the Node
static class Node{
int x;
Node link;
Node(int x){
this.x = x;
link = null;
}
}
  
static public void reverse(){
//Start from the head node
Node present = head;
Node prev = null;
//Iterate through all the elements in the list
while(present!=null){
//Store the next element in this variable
Node next = present.link;
//Changing the ilnk of the present node to the previously visited node
present.link = prev;
//Changing the previous node to the present node
prev = present;
//Moving to the next node by chaning the present
present = next;
}
head = prev;
}
static Node head;
public static void main(String[] args) throws IOException{
head = new Node(1);
Node a = new Node(2);
head.link = a;
Node b = new Node(3);
a.link = b;
Node c = new Node(4);
b.link = c;
//EG ;: 1 -- > 2 -- > 3 -- > 4
reverse();
Node t = head;
while(t!=null){
System.out.println(t.x);
t = t.link;
}
}
}