public void bringToRoot(Key k) {
        root = bringToRoot(k, root);
        printTree(root);
    }
    public Node bringToRoot(Key k, Node x) {

        if(x == null) { return x; }
        if(isChildOfCurrent(k, x)) {
            if(k.compareTo(x.right.key) == 0) { return rotateLeft(x); }
            else if(k.compareTo(x.left.key) == 0){ return rotateRight(x);}
        }
        else{
            if(k.compareTo(x.key) < 0) { return bringToRoot(k, x.left); }
            else                       { return bringToRoot(k, x.right); }
        }
        StdOut.println(x.N);
        return x;
    }
    private Boolean isChildOfCurrent(Key k, Node x) {
        if(k.compareTo(x.left.key) == 0) { return true; }
        if(k.compareTo(x.right.key) == 0) { return true; }
        return false;
    }

    public void printTree(Node x) {
        if( x == null) return;
        printTree(x.left);
        StdOut.print(" " + x.key + " ");
        printTree(x.right);
    }

    private Node rotateLeft(Node h) {
        //if(h.right == null) { return h; }
        Node x = h.right;
        h.right = x.left;
        x.left = h;
        x.N = h.N;
        h.N = size(h.left) + size(h.right) + 1;
        return x;
    }
    private Node rotateRight(Node h) {
        //if(h.left == null ) { return h; }
        Node x = h.left;
        h.left = x.right;
        x.right = h;
        x.N = h.N;
        h.N = size(h.left) + size(h.right) + 1;
        return x;
    }