// This class represents a tree of integers
public class IntTree {
    private IntTreeNode overallRoot;

    // Constructs a tree with default numbers
    public IntTree() {
        // overallRoot = null;
        IntTreeNode overall = new IntTreeNode(17);
        overallRoot.left = new IntTreeNode(41);
        overallRoot.right = new IntTreeNode(9);
        overallRoot.left.left = new IntTreeNode(29);
        overallRoot.left.right = new IntTreeNode(6);
        overallRoot.right.left = new IntTreeNode(81);
        overallRoot.right.right = new IntTreeNode(40);
    }

    // prints the numbers in this tree in a pre-order fashion.
    public void print() {
        print(overallRoot);
    }

    // prints the numbers of the subtree rooted at root
    // using a pre-order traversal.
    private void print(IntTreeNode root) {
        if (root != null) {
            System.out.print(root.data + " ");
            // print the left
            print(root.left);
            // print the right
            print(root.right);
        }
    }

    // Returns true if n is in this tree, false otherwise.
    public boolean contains(int n) {
        return contains(overallRoot, n);
    }

    // Returns true if n appears as the data for a node in the sub-tree rooted
    // at root. Returns false if the tree is empty.
    private boolean contains(IntTreeNode root, int n) {
        if (root == null) {
            return false;
        } else if (root.data == n) {
            return true;
        } else {
            return contains(root.left, n) || contains(root.right, n);
        }
    }
}