摘要:
题目描述 Find the number of strings s of length N consisting of 'A', 'B', and 'C' that satisfy the following condition:·s can be converted to the empty st 阅读全文
摘要:
题目描述 At the main street of Byteland, there will be built n skyscrapers, standing sequentially one next to other. If look leftside right, sequence of t 阅读全文