USACO - 随笔分类 - superbin

USACO 2.2 Party Lamps

摘要：类型：枚举描述：Party LampsIOI 98To brighten up the gala dinner of the IOI'98 we have a set of N(10 <= N <= 100) colored lamps numbered from 1 to N.The lamps are connected to four buttons:Button 1: Whe... 阅读全文

posted @ 2010-07-30 11:27 superbin 阅读(647) 评论(0) 推荐(0)

USACO 2.2 Runaround Numbers

摘要：Problem 57: Runaround NumbersRunaround numbers are integers with unique digits, none of which is zero (e.g., 81362) that also have an interesting property, exemplified by this demonstration: If you st... 阅读全文

posted @ 2010-07-12 10:37 superbin 阅读(423) 评论(0) 推荐(0)

USACO 2.2 Subset Sums

摘要：Problem 38: Subset SumsFor many sets of consecutive integers from 1 through N (1 <= N <= 39), one can partition the set into two sets whose sums are identical. For example, if N=3, one can parti... 阅读全文

posted @ 2010-07-11 16:21 superbin 阅读(806) 评论(0) 推荐(0)

USACO 2.2 Preface Numbering

摘要：Problem 92: Preface NumberingA certain book's prefaces are numbered in upper case Roman numerals. Traditional Roman numeral values use a single letter to represent a certain subset of decimal numbers.... 阅读全文

posted @ 2010-07-11 15:38 superbin 阅读(509) 评论(0) 推荐(0)

USACO 2.1 Hamming Codes

摘要：Problem 94: Hamming CodesRob Kolstad Given N, B, and D: Find a set of N codewords (1 <= N <= 64), each of length B bits (1 <= B <= 8), such that each of the codewords is at least Hamming d... 阅读全文

posted @ 2010-06-03 18:43 superbin 阅读(305) 评论(0) 推荐(0)

USACO 2.1 Sorting A Three-Valued Sequence

摘要：Type: tricky题目描述：Sorting a Three-Valued SequenceSorting is one of the most frequently performed computational tasks. Consider the special sorting problem in which the records to be sorted have at most... 阅读全文

posted @ 2010-06-01 20:21 superbin 阅读(307) 评论(0) 推荐(0)

USACO 2.1 Ordered Fractions

摘要：很简单的一道题直接找出所有的分数，然后按值排序，去除重复的输出。my code标程一：改进：1.发现这些分数的分子和分母互素2.排序的时候的小技巧：p1/q1 = p2/q2 --> p1*q2 = p2*q1stand1标程二：改进：1.找出这些分数之间的规律，然后直接生成stand2 阅读全文

posted @ 2010-05-30 18:50 superbin 阅读(225) 评论(0) 推荐(0)

USACO 2.1 The Castle

摘要：Type:无向图的连通分支描述：一个m*n的城堡，有一些墙分隔了若干房间，求房间数，及最大的房间，和拆掉一堵墙后能得到的最大房间。思路：先DFS，然后遍历m*n，根据最西边、最南边的规则，只考虑去掉东边北边的墙。Process:写的很垃圾，wa6次，刚开始“Choose the optimal wall to remove from the set of optimal walls b... 阅读全文

posted @ 2010-05-29 17:04 superbin 阅读(521) 评论(0) 推荐(0)

USACO 1.5 Checker Challenge

摘要：题目描述：n皇后问题，规模6－13，按顺序输出前三组解，再输出总解数。前一段学了点DLX的皮毛，就用它做了做，谁知道前三组解得输出顺序老出错。于是就放弃了。看了hint，就暴搜了一回，开了4个数组，记录行、列、'/'，'\'，的放皇后的情况，根据对称性，搜一半就行了。my code看了解题报告，发现自己写的好烂，首先，不需要记录行（why?），其次，直接记录个数，标记是多余的。standard这个... 阅读全文

posted @ 2010-05-25 21:24 superbin 阅读(404) 评论(0) 推荐(0)

USACO 1.5 Prime Palindromes

摘要：1.生成回文数（100000000以内）大概20000个2.判断素数生成回文数的算法思想：分别生成数位是奇odd，和数位是偶even的回文数，对于串1234, 翻转一下 4321，再接上就生成了一个回文数，odd:1234321 even:12344321实现的方法可以多种多样。我用的是递归的方法。代码阅读全文

posted @ 2010-05-22 18:48 superbin 阅读(208) 评论(0) 推荐(0)

USACO 1.4 Packing Rectangles

摘要：这个题好久以前就看过了，但当时没思路，现在重新看，发现还是可以做的。思路：根据题目给出的六种layout，对每种的每个位置有4中选择（即4个矩形)，另外4个矩形旋转后又可形成4个矩形。基本上是枚举所有的情况，然后找最小的面积值。最后一种layout，其实又要分四种情况的。代码阅读全文

posted @ 2010-05-22 16:51 superbin 阅读(433) 评论(0) 推荐(0)

USACO 1.4 Mother's Milk

摘要：比较经典的3个杯子互相倒水的问题。状态即3个杯子中的水量，用一个3维数组记录，转移为六种组合。code 阅读全文

posted @ 2010-05-22 16:45 superbin 阅读(307) 评论(0) 推荐(0)

USACO 1.4 Arithmetic Progressions

摘要：按步长递增的顺序搜索，先预处理出所有可能的步长，及位置值（用flg[]标记），再深搜预处理稍微有点麻烦code 阅读全文

posted @ 2010-05-22 16:41 superbin 阅读(294) 评论(0) 推荐(0)

USACO 1.4 The clocks

摘要：USACO都荒废好久了，今年都没怎么做，今天突然想做做一道搜索题，写了个很**的算法，开了9维的数组保存状态，能写成这样也不容易啊，时间复杂度可想而知，因为用的广搜，空间就更。。。一看解题报告，太伤人了，居然有O(1)的算法！我的代码来看看解题报告吧：Analysis 58: The ClocksNotice that the order in which we apply moves is ir... 阅读全文

posted @ 2010-05-14 17:37 superbin 阅读(698) 评论(0) 推荐(1)

superbin

随笔分类 - USACO

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