BST

import java.util.TreeSet;
class TreeNode{
    int value;
    TreeNode right,left;
    TreeNode(int a){
        value=a;
    }
}
class BSTTest{
    TreeNode root;
    void insert(int value)
    {
        root=insertNode(root,value);
    }
    TreeNode insertNode(TreeNode root,int value)
    {
        if(root==null)
            return new TreeNode(value);
        if(root.value>value)
            root.left=insertNode(root.left,value);
        else if(root.value<value)
            root.right=insertNode(root.right,value);
        return root;
    }
    void inorder(){
        inorderNodes(root);
        System.out.println(" ");
    }
    void inorderNodes(TreeNode root)
    {
        if(root!=null)
        {
            inorderNodes(root.left);
            System.out.print(root.value+" ");
            inorderNodes(root.right);
        }
    }
    void preorder(){
        preorderNodes(root);
        System.out.println(" ");
    }
    void preorderNodes(TreeNode root)
    {
        if(root!=null)
        {
            System.out.print(root.value+" ");
            preorderNodes(root.left);
            preorderNodes(root.right);
        }
    }
    void postorder(){
        postorderNodes(root);
        System.out.println(" ");
    }
    void postorderNodes(TreeNode root)
    {
        if(root!=null)
        {
            postorderNodes(root.left);
            postorderNodes(root.right);
            System.out.print(root.value+" ");
        }
    }
    public static void main(String[] args)
    {
        BSTTest tree = new BSTTest();
        TreeSet ts=new TreeSet();
        int[] values={10,58,42,63,15,0,42,14};
        for(int a:values)
        {
            tree.insert(a);
            ts.add(a);
        }
        System.out.println("Inorder traversals");
        tree.inorder();
        System.out.println("preorder traversals");
        tree.preorder();
        System.out.println("postorder traversals");
        tree.postorder();
    }
}