摘要： The Old Frog King lives on the root of an infinite tree. According to the law, each node should connect to exactly two nodes on the next level, formin 阅读全文

摘要： A frog has just learned some number theory, and can't wait to show his ability to his girlfriend. Now the frog is sitting on a grid map of infinite ro 阅读全文

摘要： Limak is a little bear who loves to play. Today he is playing by destroying block towers. He built n towers in a row. The i-th tower is made of hi ide 阅读全文

摘要： The cows are having a picnic! Each of Farmer John's K (1 ≤ K ≤ 100) cows is grazing in one of N (1 ≤ N ≤ 1,000) pastures, conveniently numbered 1...N. 阅读全文

摘要： You are given a sequence of numbers a1, a2, ..., an, and a number m. Check if it is possible to choose a non-empty subsequence aij such that the sum o 阅读全文

摘要： One traveler travels among cities. He has to pay for this while he can get some incomes. Now there are n cities, and the traveler has m days for trave 阅读全文

摘要： In the capital city of Berland, Bertown, demonstrations are against the recent election of the King of Berland. Berland opposition, led by Mr. Ovalny, 阅读全文

摘要： Little Q loves playing with different kinds of graphs very much. One day he thought about an interesting category of graphs called ``Cool Graph'', whi 阅读全文

摘要： Every year the cows hold an event featuring a peculiar version of hopscotch that involves carefully jumping from rock to rock in a river. The exciteme 阅读全文

摘要： there are N ACMers in HDU team. ZJPCPC Sunny Cup 2007 is coming, and lcy want to select some excellent ACMers to attend the contest. There have been M 阅读全文

摘要： Two players play a game. The game is played on a rectangular board with n × m squares. At the beginning of the game two different squares of the board 阅读全文

摘要： To confuse the opponents, the Galactic Empire represents fractions in an unusual format. The fractions are represented as two sets of integers. The pr 阅读全文