【ZOJ】3959.Problem Preparation

It's time to prepare the problems for the 14th Zhejiang Provincial Collegiate Programming Contest! Almost all members of Zhejiang University programming contest problem setter team brainstorm and code day and night to catch the deadline, and empty bottles of Marjar Cola litter the floor almost everywhere!


A checksum is an algorithm that scans a packet of data and returns a single number. The idea is that if the packet is changed, the checksum will also change, so checksums are often used for detecting transmission errors, validating document contents, and in many other situations where it is necessary to detect undesirable changes in data.


How far can you make a stack of cards overhang a table? If you have one card, you can create a maximum overhang of half a card length. (We're assuming that the cards must be perpendicular to the table.) With two cards you can make the top card overhang the bottom one by half a card length, and the bottom one overhang the table by a third of a card length, for a total maximum overhang of 1/2 + 1/3 = 5/6 card lengths.


In the Test of English as a Foreign Language (TOEFL), the listening part is very important but also very hard for most students since it is usually quite hard for them to remember the whole passage. To help themselves memorize the content, students can write down some necessary details. However, it is not easy to write down the complete word because of its length. That's why we decide to use the abbreviation to express the whole word.


有一群人,打乒乓球比赛,两两捉对撕杀,每两个人之间最多打一场比赛。 球赛的规则如下: 如果A打败了B,B又打败了C,而A与C之间没有进行过比赛,那么就认定,A一定能打败C。 如果A打败了B,B又打败了C,而且,C又打败了A,那么A、B、C三者都不可能成为冠军。 根据这个规则,无需循环较量,或许就能确定冠军。你的任务就是面对一群比赛选手,在经过了若干场撕杀之后,确定是否已经实际上产生了冠军。

【ZOJ】3326.An Awful Problem

In order to encourage Hiqivenfin to study math, his mother gave him a sweet candy when the day of the month was a prime number. Hiqivenfin was happy with that. But several days later, his mother modified the rule so that he could get a candy only when the day of the month was a prime number and the month was also a prime number.