I have written a program that takes a linked list and then converts it to a stack.
I would like a code review for my program. Thanks in advance.
Stack.java
/**
* Created by Ninan John J P on 2/8/2016.
*/
public class Stack {
int stackArray[];
int topOfStack=-1;
LinkedList source;
int stackSize;
public Stack(LinkedList l1) {
source=l1;
stackSize=l1.count;
stackArray= new int[stackSize];
}
private void put(int data) {
stackArray[++topOfStack]=data;
}
private int pop(){
return stackArray[topOfStack--];
}
public static void main(String...a){
LinkedList l1= new LinkedList();
l1.getInitialData();
l1.create();
Stack s1= new Stack(l1);
Node currentNode=l1.head;
s1.put(Integer.parseInt(currentNode.getData()));
while(currentNode.getNextNode()!=null) {
currentNode=currentNode.getNextNode();
s1.put(Integer.parseInt(currentNode.getData()));
}
System.out.println("The Stack is:");
while(s1.topOfStack>=0)
System.out.print(s1.pop() + "\t");
}
}
LinkedList.java
/**
* Created by Ninan John J P on 2/3/2016.
*/
import java.util.Scanner;
public class LinkedList {
boolean createFlag=false;
int noOfInitialNodes;
Node head;
int count=0;
private void findElement() {
String toFind;
boolean found=false;
int index=0;
Scanner in = new Scanner(System.in);
System.out.println("Enter Number to Find");
toFind=in.next();
if(count<=0)
System.out.println("List is Empty");
else {
Node currentNode=head;
while(currentNode!=null&&!found){
if(currentNode.getData().equals(toFind)){
System.out.println("Found At " + (index+1));
found = true;
}
else{
currentNode=currentNode.getNextNode();
index++;
}
}
}
if (!found)
System.out.println("Not Found");
}
private Node findElementNode(String toFind) {
Node currentNode;
if(count<=0)
System.out.println("List is Empty");
else {
currentNode=head;
while(currentNode!=null){
if(currentNode.getData().equals(toFind))
return currentNode;
else if(currentNode.getNextNode()!=null) {
if (currentNode.getNextNode().getData().equals(toFind))
return currentNode;
}
currentNode=currentNode.getNextNode();
}
}
return null;
}
private void deleteList() {
head.setNext(null);
head=null;
}
private void deleteNode() {
Scanner in= new Scanner(System.in);
String numToDelete;
System.out.println("Enter the number to delete");
numToDelete=in.nextLine();
Node currentNode;
currentNode=findElementNode(numToDelete);
if(currentNode==null)
System.out.println("Element Not found");
else if(currentNode==head)
head = currentNode.getNextNode();
else if (currentNode.getNextNode()!=null) {
if(currentNode.getNextNode().getNextNode()!=null)
currentNode.setNext(currentNode.getNextNode().getNextNode());
else
currentNode.setNext(null);
}
}
private void print() {
Node currentNode= head;
if(head==null) {
System.out.println("List Does not Exist");
main();
}
System.out.print(currentNode.getData());
while(currentNode.getNextNode()!=null){
currentNode=currentNode.getNextNode();
System.out.print("-->" + currentNode.getData());
}
}
private void insertNew() {
Scanner in = new Scanner(System.in);
String data;
System.out.println("Enter Data for Node:");
data=in.next();
Node tempNode= new Node(data);
Node currentNode=head;
if(currentNode!=null){
while(currentNode.getNextNode()!=null)
currentNode=currentNode.getNextNode();
currentNode.setNext(tempNode);
}
count++;
}
public void insertAtPos(){
Scanner in = new Scanner(System.in);
String data;
int index;
if(head!=null) {
System.out.println("Enter Data for Node:");
data = in.next();
System.out.println("Enter the position");
index = in.nextInt();
Node tempNode = new Node(data);
Node currentNode = head;
if (currentNode != null) {
for (int i = 1; i < index - 1 && currentNode.getNextNode() != null; i++)
currentNode = currentNode.getNextNode();
if (index != 1) {
tempNode.setNext(currentNode.getNextNode());
currentNode.setNext(tempNode);
}
else {
tempNode.setNext(head);
head = tempNode;
}
count++;
}
}
}
protected void create() {
if(!createFlag) {
createFlag=true;
int i = 0;
Scanner in = new Scanner(System.in);
String data;
System.out.println("Enter Data for head Element:");
data = in.next();
head = new Node(data);
count++;
while (i < noOfInitialNodes-1) {
insertNew();
i++;
}
}
else
System.out.println("List is aready Created... Insert new elements");
}
protected void getInitialData() {
Scanner in = new Scanner(System.in);
System.out.print("\nEnter Initial Number of Nodes:");
noOfInitialNodes=in.nextInt();
}
public static void main(String...a){
LinkedList l1= new LinkedList();
Scanner in = new Scanner(System.in);
int choice;
do {
System.out.println("\nEnter a Number between 1-6");
System.out.println("1}Insert At Position\n2)Delete Node\n3)Delete List\n4)Find\n5)Create\n6)Print\n7)Exit\n8)Insert At End");
choice= in.nextInt();
switch (choice) {
case 1:
l1.insertAtPos();
l1.print();
break;
case 2:
l1.deleteNode();
l1.print();
break;
case 3:
l1.deleteList();
break;
case 4:
l1.findElement();
break;
case 5:
l1.getInitialData();
l1.create();
l1.print();
break;
case 6:
l1.print();
break;
case 7:
System.exit(0);
break;
case 8:
l1.insertNew();
l1.print();
break;
}
}while(choice<9);
}
}
Node.java
/**
* Created by Ninan John J P on 2/6/2016.
*/
class Node{
String data;
Node next;
public Node(String objdata){
next= null;
data=objdata;
}
public Node(String objData, Node nextNode){
next=nextNode;
data=objData;
}
public Node getNextNode(){
return next;
}
public String getData(){
return data;
}
public void setData(String objData){
data=objData;
}
public void setNext(Node nextNode){
next= nextNode;
}
}
LinkedListandStackalready, and they're in the standard library. – Pimgd Jun 8 '16 at 13:49