YOONGI

Drainage Ditches Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is covered by water for awhile and takes quite a long tim...

A power network consists of nodes (power stations, consumers and dispatchers) connected by power transport lines. A node u may be supplied with an amount s(u) >= 0 of power, may produce an amount 0...

ACM Computer Factory As you know, all the computers used for ACM contests must be identical, so the participants compete on equal terms. That is why all these computers are historically produced a...

PIGS题目链接：http://poj.org/problem?id=1149Mirko works on a pig farm that consists of M locked pig-houses and Mirko can't unlock any pighouse because he doesn't have the keys. Customers come to the fa...

Ombrophobic BovinesFJ's cows really hate getting wet so much that the mere thought of getting caught in the rain makes them shake in their hooves. They have decided to put a rain siren on the farm t...

Coding ContestA coding contest will be held in this university, in a huge playground. The whole playground would be divided into N blocks, and there would be M directed paths linking these blocks...