秋心无波

摘要： 1203. Scientific ConferenceTime limit: 1.0 second Memory limit: 64 MBFunctioning of a scientific conference is usually divided into several simultaneous sections. For example, there may be a section on parallel computing, a section on visualization, a section on data compression, and so on.Obviously 阅读全文

摘要： 1146. Maximum SumTime limit: 1.0 second Memory limit: 64 MBGiven a 2-dimensional array of positive and negative integers, find the sub-rectangle with the largest sum. The sum of a rectangle is the sum of all the elements in that rectangle. In this problem the sub-rectangle with the largest sum is re 阅读全文

摘要： 1119. MetroTime limit: 0.5 second Memory limit: 64 MBMany of SKB Kontur programmers like to get to work by Metro because the main office is situated quite close the station Uralmash. So, since a sedentary life requires active exercises off-duty, many of the staff — Nikifor among them — walk from the 阅读全文

摘要： 1013. K-based Numbers. Version 3Let’s consider K-based numbers, containing exactly N digits. We define a number to be valid if its K-based notation doesn’t contain two successive zeros. For example:1010230 is a valid 7-digit number;1000198 is not a valid number;0001235 is not a 7-digit number, it is 阅读全文

摘要： 正如我们所知道的，Floyd算法用于求最短路径。Floyd算法可以说是Warshall算法的扩展，三个for循环就可以解决问题，所以它的时间复杂度为O(n^3)。Floyd算法的基本思想如下：从任意节点A到任意节点B的最短路径不外乎2种可能，1是直接从A到B，2是从A经过若干个节点X到B。所以，我们假设Dis(AB)为节点A到节点B的最短路径的距离，对于每一个节点X，我们检查Dis(AX) + Dis(XB) B，我们只能发现一条路径，就是A->B，路径距离为9。而这显然是不正确的，真实的最短路径是A->D->C->B，路径距离为6。造成错误的原因就是我们把检查所有节点 阅读全文

摘要： Problem DescriptionA palindrome is a symmetrical string, that is, a string read identically from left to right as well as from right to left. You are to write a program which, given a string, determines the minimal number of characters to be inserted into the string in order to obtain a palindrome.A 阅读全文

摘要： Problem DescriptionIt is well known that a human gene can be considered as a sequence, consisting of four nucleotides, which are simply denoted by four letters, A, C, G, and T. Biologists have been interested in identifying human genes and determining their functions, because these can be used to di 阅读全文

摘要： Problem DescriptionFew know that the cows have their own dictionary with W (1 ≤ W ≤ 600) words, each containing no more 25 of the characters 'a'..'z'. Their cowmunication system, based on mooing, is not very accurate; sometimes they hear words that do not make any sense. For instance 阅读全文

摘要： Problem DescriptionThe cows don't use actual bowling balls when they go bowling. They each take a number (in the range 0..99), though, and line up in a standard bowling-pin-like triangle like this: 7 3 8 8 1 0 2 7 4 4 4 5 2 6 5Then the other cows traverse... 阅读全文

摘要： Problem DescriptionThe relative frequency of characters in natural language texts is very important for cryptography. However, the statistics vary for different languages. Here are the top 9 characters sorted by their relative frequencies for several common languages:English: ETAOINSHRGerman: ENIRS. 阅读全文