public static boolean test5(BinTreeNode node) {
        boolean[] res = {true};
        getHeight(node, 1, res);
        
        return res[0];
    }
    
    public static int getHeight(BinTreeNode node,int level,boolean[] res) {
        if (node==null) {
            return level;
        }
        int lh = getHeight(node.left, level+1, res);
        if (!res[0]) {
            return level;
        }
        int rh = getHeight(node.right, level+1, res);
        if (!res[0]) {
            return level;
        }
        if (Math.abs(lh-rh)>1) {
            res[0]=false;
        }
        return Math.max(lh, rh);
    }