// CSE 143, summer 2012
// An BinarySearchTree object represents an entire binary search tree of ints.
// class invariant:
// left sub tree values are less than the root
// right sub tree values are greater than the root
public class SearchTree {
	private IntTreeNode overallRoot;
	
	// Constructs an empty binary tree
	public SearchTree() {
		overallRoot = null;
	}

	// Constructs a binary tree with the given node as its root.
	public SearchTree(IntTreeNode overallRoot) {
		this.overallRoot = overallRoot;
	}

	// Prints all elements of this tree in left to right order.
	public void print() {		
		print(overallRoot);		
	}
	
	// Prints a portion of the overall tree
	private void print (IntTreeNode root) {
		if (root != null) {
			// print left
			print(root.left);
			
			// prints data
			System.out.print (root.data + " ");
			
			// print right
			print(root.right);
			
		}
	}
	
	// Returns true if the overall tree contains the given target value,
	// false otherwise
	public boolean contains (int value) {
		return contains (overallRoot, value);
	}
	
	// Returns true if a portion of the overall tree contains the given
	// target value, false otherwise.
	private boolean contains (IntTreeNode node, int value) {
		if (node == null) {
			return false;
		} else if (node.data == value) {
			return true;
		} else if (value < node.data) {
			return contains (node.left, value);		
		} else {
			return contains (node.right, value);
		}
	}
	
	// Adds the value to the tree such that sorted BST order is maintained
	public void add (int value) {
		overallRoot = add (overallRoot, value);
	}
	
	// Adds the value to the given subtree.  Does not add duplicates.
	// A node's initial state is passed in and it modified 
	// state is returned.  This is the x = change(x) pattern and
	// it allows attaching new nodes to the tree.
	private IntTreeNode add (IntTreeNode node, int value) {
		if (node == null) {
			node = new IntTreeNode(value);
		} else if (value < node.data) {
			node.left = add (node.left, value);		
		} else if (value > node.data) {
			node.right = add (node.right, value);
		} 
		return node;
	}

	
}