摘要：
题目：DescriptionDr lee cuts a string S into N pieces,s[1],…,s[N].Now, Dr lee gives you these N sub-strings: s[1],…s[N]. There might be several possibilities that the string S could be. For example, if Dr. lee gives you three sub-strings {“a”,“ab”,”ac”}, the string S could be “aabac”,”aacab”,”abaac”,…Y 阅读全文