public static void q1 (BinNode<Integer> bt)
    {
        if(bt == null)
            return;

        if(bt.getValue()%2==0)
            bt.setValue(bt.getValue()/2);

        q1(bt.getLeft());
        q1(bt.getRight());
    }

    public static void q2 (BinNode<Integer>bt)
    {

        if(bt == null)
            return;

        if( (!(bt.hasLeft())) && bt.hasRight())
            bt.setLeft(new BinNode<Integer>(0));

        if( (!(bt.hasRight())) && bt.hasLeft())
            bt.setRight(new BinNode<Integer>(0));

        q2(bt.getLeft());
        q2(bt.getRight());
    }

    public static int q3 (BinNode<Integer>bt)
    {
        if(bt == null)
            return 0;

        if(bt.getValue()%2==0)
            return 1 + q3(bt.getLeft()) + q3(bt.getRight());

        return q3(bt.getLeft()) + q3(bt.getRight());
    }

    public static int q4 (BinNode<Integer>bt)
    {
        if(bt == null)
            return 0;

        if(bt.hasRight())
            return bt.getRight().getValue() + q4(bt.getLeft()) + q4(bt.getRight());

        return q4(bt.getLeft());
    }

    public static boolean q5 (BinNode<Character>bt,char x)
    {
        if(bt == null)
            return false;

        if(bt.getValue() == x)
            return true;

        return q5(bt.getLeft(),x) || q5(bt.getRight(),x);
    }

    public static boolean q6 (BinNode<Integer>bt)
    {
        if(bt == null)
            return true;

        if(bt.getValue()%2!=0)
            return false;

        return q6(bt.getLeft()) && q6(bt.getRight());
    }

    public static int q7(BinNode<Integer>bt)
    {
        if(bt==null)
            return 0;
        return bt.getValue() + Math.max(q7(bt.getLeft()),q7(bt.getRight()));
    }

    public static boolean ezer(BinNode<Integer>bt,int sum,int treesum)
    {
        if(bt==null)
            return false;

        treesum += bt.getValue();

        if( treesum == sum && (!(bt.hasLeft())) && (!(bt.hasRight())) )
            return true;

        return ezer(bt.getLeft(),sum,treesum) || ezer(bt.getRight(),sum,treesum);
    }

    public static boolean rootsum(BinNode<Integer>bt,int sum)
    {
        return ezer(bt,sum,0);
    }