// An IntSearchTree object represents an entire binary search tree of ints.
// Class invariant: 
//    - nodes to the left of a root have smaller values
//    - nodes to the right of a root have larger values
//	  - there are no duplicates
public class IntSearchTree {
	private IntTreeNode overallRoot;

	// Constructs an empty binary tree
	public IntSearchTree() {
		overallRoot = null;
	}

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

	// returns true if the value is found in this tree, false otherwise
	public boolean contains(int value) {
		return contains(overallRoot, value);
	}

	private boolean contains(IntTreeNode root, int value) {
		if (root == null) {
			return false;
		} else if (root.data == value) {
			return true;
		} else if (value < root.data) {
			return contains(root.left, value);
		} else {
			return contains(root.right, value);
		}
	}

	// adds a value to the bst
	// post: the tree is still a valid bst
	public void add(int value) {
		overallRoot = add(overallRoot, value);
	}
	
	private IntTreeNode add(IntTreeNode root, int value) {
		if (root == null) {
			root = new IntTreeNode(value);
			//return root; // useful for visualizing with jGRASP debugger
		} else if (value < root.data) {
			root.left = add(root.left, value);
		} else if (value > root.data) {
			root.right = add(root.right, value);
		}
		return root;
	}

	// Prints a pre-order traversal of this tree.
	public void printPreOrder() {
		printPreOrder(overallRoot);
		System.out.println();
	}

	// Prints a pre-order traversal of the tree starting at the specified root
	private void printPreOrder(IntTreeNode root) {
		// implicit base case: do nothing if we reach a null root
		if (root != null) {
			System.out.print(root.data + " ");
			printPreOrder(root.left);
			printPreOrder(root.right);
		}
	}

	// Prints an in-order traversal of this tree.
	public void printInOrder() {
		printInOrder(overallRoot);
		System.out.println();
	}

	// Prints an in-order traversal of the tree starting at the specified root
	private void printInOrder(IntTreeNode root) {
		if (root != null) {
			printInOrder(root.left);
			System.out.print(root.data + " ");
			printInOrder(root.right);
		}
	}

	// Prints a post-order traversal of this tree.
	public void printPostOrder() {
		printPostOrder(overallRoot);
		System.out.println();
	}

	// Prints a post-order traversal of the tree starting at the specified root
	private void printPostOrder(IntTreeNode root) {
		if (root != null) {
			printPostOrder(root.left);
			printPostOrder(root.right);
			System.out.print(root.data + " ");
		}
	}
}