1651: [Usaco2006 Feb]Stall Reservations 专用牛棚 Time Limit: 10 Sec Memory Limit: 64 MB Submit: 700 Solved: 393 [Submit][Status][Discuss] Description Oh those picky N (1 <= N <= 50,000) cows! They are so picky that each one will only be milked over some precise time interval A..B (1 <= A <= B <= 1,000,000), …

1650: [Usaco2006 Dec]River Hopscotch 跳石子 Time Limit: 5 Sec Memory Limit: 64 MB Submit: 440 Solved: 290 [Submit][Status][Discuss] Description 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 excitement takes place on a long, …

Time Limit: 5 Sec Memory Limit: 64 MB Submit: 504 Solved: 265 [Submit][Status][Discuss] Description The cows are building a roller coaster! They want your help to design as fun a roller coaster as possible, while keeping to the budget. The roller coaster will be built on a long linear stretch of land of length L (1 …

1648: [Usaco2006 Dec]Cow Picnic 奶牛野餐 Time Limit: 5 Sec Memory Limit: 64 MB Submit: 562 Solved: 352 [Submit][Status][Discuss] Description 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. The pastures are …

1646: [Usaco2007 Open]Catch That Cow 抓住那只牛 Time Limit: 5 Sec Memory Limit: 64 MB Submit: 915 Solved: 441 [Submit][Status][Discuss] Description Farmer John has been informed of the location of a fugitive cow and wants to catch her immediately. He starts at a point N (0 <= N <= 100,000) on a number line and the cow …

1644: [Usaco2007 Oct]Obstacle Course 障碍训练课 Time Limit: 5 Sec Memory Limit: 64 MB Submit: 451 Solved: 226 [Submit][Status][Discuss] Description 考虑一个 N x N (1 <= N <= 100)的有1个个方格组成的正方形牧场。有些方格是奶牛们不能踏上的，它们被标记为了'x'。例如下图： . . B x . . x x A . . . . x . . x . . . . . x . . 贝茜发现自己恰好在点A处，她想去B处的盐块舔盐。缓慢而且笨拙的动物，比如奶牛，十分讨厌转弯。尽管 …

1643: [Usaco2007 Oct]Bessie's Secret Pasture 贝茜的秘密草坪 Time Limit: 5 Sec Memory Limit: 64 MB Submit: 330 Solved: 278 [Submit][Status][Discuss] Description 农夫约翰已经从他的牧场中取得了数不清块数的正方形草皮，草皮的边长总是整数（有时农夫约翰割草皮的刀法不合适，甚至切出了边长为0的正方形草皮），他已经把草皮放在了一个奶牛贝茜已经知道的地方。 贝茜总是希望把美味的草皮放到她的秘密庄园里，她决定从这些草皮中取出恰好4块搬到她的秘密庄园中，然后把它们分成1×1的小块，组成一个面积 …

Time Limit: 5 Sec Memory Limit: 64 MB Submit: 667 Solved: 389 [Submit][Status][Discuss] Description 贝茜是一只非常努力工作的奶牛，她总是专注于提高自己的产量。为了产更多的奶，她预计好了接下来的N (1 ≤ N ≤ 1,000,000)个小时，标记为0..N-1。 Farmer John 计划好了 M (1 ≤ M ≤ 1,000) 个可以挤奶的时间段。每个时间段有一个开始时间(0 ≤ 开始时间 ≤ N), 和一个结束时间 (开始时间 < 结束时间 ≤ N), 和一个产量 (1 ≤ 产量 ≤ 1,000,000) 表示可以从贝茜挤 …

1641: [Usaco2007 Nov]Cow Hurdles 奶牛跨栏 Time Limit: 5 Sec Memory Limit: 64 MB Submit: 531 Solved: 344 [Submit][Status][Discuss] Description Farmer John 想让她的奶牛准备郡级跳跃比赛，贝茜和她的伙伴们正在练习跨栏。她们很累，所以她们想消耗最少的能量来跨栏。 显然，对于一头奶牛跳过几个矮栏是很容易的，但是高栏却很难。于是，奶牛们总是关心路径上最高的栏的高度。 奶牛的训练场中有 N (1 ≤ N ≤ 300) 个站台，分别标记为1..N。所有站台之间有M (1 ≤ M ≤ 25,000)条单向 …

1640: [Usaco2007 Nov]Best Cow Line 队列变换 Time Limit: 5 Sec Memory Limit: 64 MB Submit: 710 Solved: 373 [Submit][Status][Discuss] Description FJ打算带着他可爱的N (1 ≤ N ≤ 2,000)头奶牛去参加”年度最佳老农”的比赛.在比赛中,每个农夫把他的奶牛排成一列,然后准备经过评委检验. 比赛中简单地将奶牛的名字缩写为其头字母(the initial letter of every cow),举个例子,FJ带了Bessie, Sylvia,和Dora,那么就可以缩写为BSD. FJ只需将奶牛的 …