planche

摘要： You have an array a with length n, you can perform operations. Each operation is like this: choose two adjacent elements from a, say xand y, and repla 阅读全文

摘要： What are you doing at the end of the world? Are you busy? Will you save us? Nephren is playing a game with little leprechauns. She gives them an infin 阅读全文