Skip to main content

Implement an algorithm to find nth to last element of a singly linked list

File:LinkedList.java
-------------------------------------------------------------------------------------
package org.developersbrain.solutions;

class Node<T>{
Node<T> nextNode;
T t;
int n;
Node(T t){
this.t=t;
n=0;
}
}

public class LinkedList<T> {
Node<T> head;
Node<T> tail;
int counter;

LinkedList(){
head = null;
tail = null;
counter=0;
}

void add(T t){
Node<T> newN=new Node<T>(t);
counter++;
if(head==null && tail==null){
head=newN;
tail=newN;
head.n=counter;
}else{
tail.nextNode=newN;
tail=newN;
tail.n=counter;
}
}

void traverse(){
Node<T> trNode=head;
while(trNode!=null){
System.out.print(trNode.t.toString()+"-->");
trNode=trNode.nextNode;
}
System.out.println("List Ends");
}

void traverse(int n){
Node<T> trNode=head;
if(n>counter){
System.out.println("Oops! List is smaller than you think!");
return;
}

System.out.println("Printing elements from position:"+n);
while(trNode!=null){
if(n==trNode.n){
System.out.print(trNode.t.toString()+"-->");
n++;
}trNode=trNode.nextNode;
}
System.out.println("List Ends");
}


}

File:MainClass.java
------------------------------------------------------------------------------------
package org.developersbrain.solutions;

public class MainClass {

public static void main(String[] args) {
LinkedList<String> ll=new LinkedList<String>();
ll.add("Element 1");
ll.add("Element 2");
ll.add("Element 3");
ll.add("Element 4");
ll.add("Element 5");
ll.add("Element 6");
ll.add("Element 7");
ll.add("Element 8");
ll.add("Element 9");
ll.add("Element 10");
ll.add("Element 11");
ll.add("Element 12");
ll.add("Element 13");
ll.add("Element 14");
ll.add("Element 15");
ll.add("Element 16");
ll.add("Element 17");
ll.add("Element 18");
ll.add("Element 19");
ll.add("Element 20");
ll.add("Element 21");
ll.add("Element 22");
ll.add("Element 23");
ll.add("Element 24");
ll.add("Element 25");
ll.add("Element 26");
ll.add("Element 27");
ll.add("Element 28");
ll.add("Element 29");
ll.add("Element 30");
ll.add("Element 31");
ll.add("Element 32");
ll.add("Element 33");
ll.add("Element 34");
ll.add("Element 35");
ll.add("Element 36");
System.out.println("Case 1:");
System.out.println("-----------------------------------");
ll.traverse(15);
System.out.println();
System.out.println();
System.out.println("Case 2:");
System.out.println("-----------------------------------");
ll.traverse(45);
}

}

Output:
-----------------------------------------------------------------------------------
Case 1:
-----------------------------------
Printing elements from position:15
Element 15-->Element 16-->Element 17-->Element 18-->Element 19-->Element 20-->Element 21-->Element 22-->Element 23-->Element 24-->Element 25-->Element 26-->Element 27-->Element 28-->Element 29-->Element 30-->Element 31-->Element 32-->Element 33-->Element 34-->Element 35-->Element 36-->List Ends


Case 2:
-----------------------------------
Oops! List is smaller than you think!



Comments

Popular posts from this blog

Java Interface

Problem Statement A Java interface can only contain method signatures and fields. Interface can be used to achieve polymorphism. In this problem you will practice your knowledge on interfaces. You are given an interface   AdvancedArithmetic   which contains a method signature   public abstract int divisorSum(int n) . You need to write a class called MyCalculator which implements the interface. divisorSum   function just takes an integer as input and return the sum of all its divisors. For example divisors of 6 are 1,2,3 and 6, so   divisorSum   should return 12. Value of n will be at most 1000. Read the partially completed code in the editor and complete it. You just need to write the MyCalculator class only.   Your class shouldn't be public. Sample Input 6 Sample Output I implemented: AdvancedArithmetic 12 Explanation Divisors of 6 are 1,2,3 and 6. 1+2+3+6=12. import java.util.*; interface AdvancedArithmetic{   p...

change directory (cd) function for an abstract file system ( Java Implementation )

Write a function that provides change directory (cd) function for an abstract file system. Notes: Root path is '/'. Path separator is '/'. Parent directory is addressable as "..". Directory names consist only of English alphabet letters (A-Z and a-z). For example, new Path("/a/b/c/d").cd("../x").getPath() should return "/a/b/c/x". Note: The evaluation environment uses '\' as the path separator. public class Path {     private String path;     public Path(String path) {         this.path = path;     }     public String getPath() {         return path;     }     public Path cd(String newPath) {         //throw new UnsupportedOperationException("Waiting to be implemented."); String[] newP=newPath.split("/");     String[] oldP=path.split("/");     int lnCount=0;     for(String str:newP){     if(st...

Java Abstract Class

Problem Statement A Java abstract class is a class that can't be instantiated, that means you cannot create new instances of an abstract class. It works as a base for subclasses. You should learn about Java Inheritence before attempting this challenge. Following is an example of abstact class: abstract class Book {     String title;     abstract void setTitle(String s);     String getTitle()     {         return title;     } } If you try to create an instance of this class like the following line you will get an error: Book new_novel=new Book(); You have to create another class that extends the abstract class. Then you can create instance of the new class. Notice that   setTitle   method is abstract too and has no body. That means you must implement the body of the that method in the child class. In the editor we have provided ...