摘要: 描述 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 think of conc 阅读全文
posted @ 2018-05-02 14:47 真想不出名字了 阅读(349) 评论(0) 推荐(0) 编辑