摘要:
Description The little cat is so famous, that many couples tramp over hill and dale to Byteland, and asked the little cat to give names to their newly 阅读全文
摘要:
Description Given two strings a and b we define a*b to be their concatenation. For example, if a = "abc" and b = "def" then a*b = "abcdef". If we thin 阅读全文