sitting here like 
suppressing the urge to help when I see him mess up in a way that he will only realise in 5 steps and then reverse them one by one. Very proud of his tenacity though.
sitting here like suppressing the urge to help when I see him mess up in a way that he will only realise in 5 steps and then reverse them one by one. Very proud of his tenacity though.
O(1) since the tower doesn't topple when stacked randomly.