// Binary Search Tree class
// Xiwei Wang

import java.util.*;

public class BST 
{
    // instance variables
    private BSTNode m_root;
    private int m_size;
    
    // constructor
    public BST()
    {
        m_root = null;
        m_size = 0;
    }
    
    // This method returns the number of elements in the tree.
    // Do not make any changes to this method!
    public int size()
    {
        return m_size;
    }
    
    // This method clears the content of the tree.
    // Do not make any changes to this method!
    public void clear()
    {
        m_root = null;
        m_size = 0;
    }    
    
    // This non-recursive method takes a string and inserts it into the binary
    // search tree, keeping the tree ordered.
    public void add(String value)
    {
        // TODO: implement this method using a non-recursive solution
    }
    
    // This non-recursive method returns a string that represents the in-order traversal
    // of the binary search tree.
    public String inOrder()
    {   
        // TODO: implement this method using a non-recursive solution
        
        return ""; // replace this statement with your own return
    } 
    
    // This method returns the smallest element in the binary search tree. You 
    // are not allowed to create any additional structures, including but not 
    // limited to arrays, stacks, queues, or other trees.
    public String min()
    {
        // TODO: implement this method using a non-recursive solution
        
        return ""; // replace this statement with your own return
    }
    
    // This method takes a reference to the root of the expression, evaluates
    // the tree, and returns the result as an int.
    public int evaluate(BSTNode node)
    {
        // TODO: implement this method using a non-recursive solution
        
        return -1; // replace this statement with your own return
    }
}