Binary Tree Array

import java.util.Scanner;

class NodeBT

{

    int info;

    boolean used;

}

public class BinaryTreeArray

{

    NodeBT node[]=new NodeBT[20];

    void MakeTree(int val)

    {

        node[0]=new NodeBT();

        node[0].info=val;

        node[0].used=true;

        for(int i=1;i<20;i++)

        {

            node[i]=new NodeBT();

            node[i].info=0;

            node[i].used=false;

        }

    }

    void setLeft(int p,int val)

    {

Binary Tree with Traversels– InOrder, PreOrder, PostOrder – (Recursive& Non-Recursive)

import java.util.Scanner;

import java.util.Stack;

public class Node

{

    int info;

    Node next,prev;

    Node left,right;

}

public class BinaryTree

{

    Node Insert(int val)

    {

        Node t=new Node();

        t.info=val;

        return(t);

    }

    void setLeft(Node p,int val)

    {

        if(p==null || p.left!=null)

            System.out.println("\nInvalid Insertion");

        else

            p.left=Insert(val);

    }

    void setRight(Node p,int val)

    {

        if(p==null || p.right!=null)

            System.out.println("\nInvalid insertion");

        else

            p.right=Insert(val);

    }

    void InRecur(Node Start)

    {

Circular Queue

import java.util.*;

public class CircularQueue

{

    int front,rear,size=5;

    int a[]=new int[size];

    CircularQueue()

    {

        front=rear=size-1;

    }

    void Insert(int n)

    {

        Ins:

        {

        if(rear==size-1)

            rear=0;

        else rear++;

        if(rear==front)

        {

            System.out.println("Overflow");

            break Ins;

Merging two Link List

import java.util.Scanner;

import java.util.Stack;

public class MergeList

{

    public static void main(String[] args)

    {

        Scanner in = new Scanner(System.in);

        SingleLL s1=new SingleLL();

        SingleLL s2=new SingleLL();

        int i,j;

        System.out.println("Enter 5 Elements for Link 1");

        for(i=0;i<5;i++)

            s1.AddEnd(in.nextInt());

        System.out.println("Enter 5 Elements for Link 2");

        for(i=0;i<5;i++)

            s2.AddEnd(in.nextInt());

        SingleLL s3=new SingleLL();

        s3=s1;

        s3.end.next=s2.start;

        Stack s=new Stack();

        s3.curr=s3.start;

        while(s3.curr!=null)

Double Link List with Operations - Add in Beginning, Add at End, Del at Beg, Del at End, Del any Element, Display, Search

import java.util.Scanner;

public class Node

{

    int info;

    Node next,prev;

    Node left,right;

}

public class DoubleLL

{

    Node start=new Node();

    Node end=new Node();

    Node curr=new Node();

    int num;

   

    DoubleLL()

    {

        start=null;

        end=null;

        num=0;

    }

    void AddBeg(int val)

    {

        Node t=new Node();

        t.info=val;

Single Link-List with Operations - Add in Beginning, Add at End, Del at Beg, Del at End, Del any Element, Display, Search

import java.util.Scanner;

public class SingleLL

{

    Node start=new Node();

    Node end=new Node();

    Node curr=new Node();

    int num;

    SingleLL()

    {

        start=null;

        end=null;

        num=0;

    }

   

    void AddBeg(int val)

    {

        Node t=new Node();

        t.info=val;

        if(num++==0)

            end=t;

        else

            t.next=start;

        start=t;

    }

    void AddEnd(int val)

    {

Stack Operations – Push, Pop & Display for Characters

import java.io.IOException;

import java.util.Scanner;

public class Stack_Char

{

    char arr[];

    int top;

   

    Stack_Char()

    {

        arr=new char[30];

        top=-1;

    }

    void Push(char val)

    {

        if(top==30)

            System.out.println("Stack OVerflow");

        else

            arr[++top]=val;

    }

   

    char Pop()

    {

        if(top==-1)

        {

            System.out.println("Stack Underflow");

            return 0;

        }

Stack Operations – Push, Pop & Display for Numbers

import java.util.Scanner;

public class Stack_Num

{

    double arr[];

    int top;

   

    void Push(double val)

    {

        if(top==9)

            System.out.println("Stack OVerflow");

        else

            arr[++top]=val;

    }

   

    double Pop()

    {

        if(top==-1)

        {

            System.out.println("Stack Underflow");

            return 0;

        }

        else

        {

            return arr[top--];

        }

    }

    void Display()

    {

        if(top==-1)

               System.out.println("Stack is Empty");

        else

        {

            System.out.println("Stack is");

            for(int i=0;i<=top;i++)

                System.out.print(arr[i] + "-");

        }

        System.out.println(" ");

    }

    boolean isEmpty()

    {

        if (top<0)

            return true;

        else

            return false;

    }

    Stack_Num()

    {

        top=-1;

        arr=new double[10];

    }

    public static void main(String[] args)

    {

        Scanner in = new Scanner(System.in);

        int ch,val;

        Stack_Num s=new Stack_Num();

        while(true)

        {

            System.out.println("Choose");

            System.out.println("1 : Push\t2 : Pop\t3 : Display\t4 : Exit");

            ch=in.nextInt();

            switch(ch)

            {

                case 1:

                {

                    System.out.println("Enter Value");

                    val=in.nextInt();

                    s.Push(val);

                    break;

                }

                case 2:

                {

                    System.out.println("Popped Value is " + s.Pop());

                    break;

                }

                case 3:

                {

                    s.Display();

                    break;

                }

                case 4:

                {

                    System.exit(0);

                }

                default:

                    System.out.println("Wrong Choice");

            }

        }

    }

}

Link List with Queue

import java.util.Scanner;

public class Node

{

    int info;

    Node next,prev;

    Node left,right;

}

public class QueueLL

{

    Node start=new Node();

    Node end=new Node();

    Node curr=new Node();

    int ch,num;

    Object obj=new Object();

    QueueLL()

    {

        start=null;

        end=null;

        num=0;

    }

    void Add(int val)

    {

Link-List with Stack

import java.util.Scanner;

public class StackLL

{

    Node start=new Node();

    Node top=new Node();

    Node curr=new Node();

    int ch,num;

    StackLL()

    {

        num=0;

        start=null;

        top=null;

    }

    void Push(int val)

    {

        Node t=new Node();

        t.info=val;

        t.next=null;

        if(num++==0)

            start=t;

        else

            top.next=t;

        top=t;

Depth First Search with Stack

import java.util.Scanner;

class Stack

{

    int stk[]=new int[10];

    int top;

    Stack()

    {

        top=-1;

    }

    void Push (int item)

    {

        if (top==9)

            System.out.println("Stack overflow");

        else

        stk[++top]=item;

    }

    boolean isEmpty()

    {

    if (top<0)

        return true;

    else

        return false;

    }

    int Pop()

    {

        if (isEmpty())

        {

Breadth First Search with Queue

import java.io.*;

import java.util.Scanner;

class Queue

{

    int items[]=new int[10];

    int front,rear;

    Queue()

    {

        front=0;

        rear=-1;

    }

    void Insert(int e)

    {

        if(rear==9)

            System.out.println("Queue overflow");

        else

            items[++rear]=e;

    }

    int Empty()

    {

        return(rear<front? 1:0);

    }