摘要： B. Unlucky TicketEach of you probably has your personal experience of riding public transportation and buying tickets. After a person buys a ticket (which traditionally has anevennumber of digits), he usually checks whether the ticket is lucky. Let us remind you that a ticket is lucky if the sum of 阅读全文

摘要： A. TwinsImagine that you have a twin brother or sister. Having another person that looks exactly like you seems very unusual. It's hard to say if having something of an alter ego is good or bad. And if you do have a twin, then you very well know what it's like.Now let's imagine a typical 阅读全文

摘要： Stockbroker GrapevineTime Limit:1000MSMemory Limit:10000KTotal Submissions:19042Accepted:10287DescriptionStockbrokers are known to overreact to rumours. You have been contracted to develop a method of spreading disinformation amongst the stockbrokers to give your employer the tactical edge in the st 阅读全文

摘要： The Cow LexiconTime Limit:2000MSMemory Limit:65536KTotal Submissions:5719Accepted:2638DescriptionFew know that the cows have their own dictionary withW(1 ≤W≤ 600) words, each containing no more 25 of the characters 'a'..'z'. Their cowmunication system, based on mooing, is not very ac 阅读全文