摘要： Tree RecoveryTime Limit:1000MSMemory Limit:65536KTotal Submissions:9879Accepted:6210DescriptionLittle Valentine liked playing with binary trees very much. Her favorite game was constructing randomly looking binary trees with capital letters in the nodes.This is an example of one of her creations: .. 阅读全文

摘要： Ubiquitous ReligionsTime Limit:5000MSMemory Limit:65536KTotal Submissions:20668Accepted:10153DescriptionThere are so many different religions in the world today that it is difficult to keep track of them all. You are interested in finding out how many different religions students in your university 阅读全文

摘要： The SuspectsTime Limit:1000MSMemory Limit:20000KTotal Submissions:18859Accepted:9130DescriptionSevere acute respiratory syndrome (SARS), an atypical pneumonia of unknown aetiology, was recognized as a global threat in mid-March 2003. To minimize transmission to others, the best strategy is to separa 阅读全文

摘要： Wild WordsTime Limit:2000MSMemory Limit:65536KTotal Submissions:4412Accepted:1149DescriptionA word is a string of lowercases. A word pattern is a string of lowercases, '?'s and '*'s. In a pattern, a '?' matches any single lowercase, and a '*' matches none or more lowe 阅读全文