BTest.java

// Binay tree by using the Array
package BTree;
public class BTest {
  int arr[];
  int lastusedindex;

  public BTest(int size) {
    arr = new int[size+1];
    this.lastusedindex = 0;
  }
  public void insert(int val)
  {
    if(arr.length-1 == lastusedindex)
    {
      System.out.println("Array is full");
    }
    else
    {
      arr[lastusedindex+1]= val;
      lastusedindex++;
    }
  }
  public void traversepreorder(int index)
  {
    if(index>lastusedindex)
    {
      return;
    }
    else {
      System.out.print(arr[index] + "  ");
      traversepreorder(index * 2);
      traversepreorder(index * 2 + 1);
    }
  }
  public void traverse(int index)
  {
    if(index>lastusedindex)
    {
      return;
    }
    else {
      traverse(index * 2);
      System.out.print(arr[index] + "   ");
      traverse(index * 2 + 1);
    }
    }
  public static void main(String[] args) {
    BTest obj = new BTest(5);
    obj.insert(13);
    obj.insert(34);
    obj.insert(42);
    obj.insert(12);
    obj.insert(78);
    obj.traverse(1);
    System.out.println();
   obj.traversepreorder(1);

  }

}