Everyone knows that DNA strands consist of nucleotides. There are four types of nucleotides: "A", "T", "G", "C". A DNA strand is a sequence of nucleotides. Scientists decided to track evolution of a rare species, wh…

Arkady needs your help again! This time he decided to build his own high-speed Internet exchange point. It should consist of n nodes connected with minimum possible number of wires into one network (a wire directly connects two nodes). Exactly k of t…

Ivan had string s consisting of small English letters. However, his friend Julia decided to make fun of him and hid the string s. Ivan preferred making a new string to finding the old one. Ivan knows some information about the string s. Namely, he re…

Pronlem A In a small restaurant there are a tables for one person and b tables for two persons. It it known that n groups of people come today, each consisting of one or two people. If a group consist of one person, it is seated at a vacant one-seate…

Polycarp watched TV-show where k jury members one by one rated a participant by adding him a certain number of points (may be negative, i. e. points were subtracted). Initially the participant had some score, and each the marks were one by one added…

题目传送门 传送门I 传送门II 传送门III 题目大意 求一个满足$d\sum_{i = 1}^{n} \left \lceil \frac{a_i}{d} \right \rceil - \sum_{i = 1}^{n} a_{i} \leqslant K$的最大正整数$d$. 整理一下可以得到条件是$d\sum_{i = 1}^{n} \left \lceil \frac{a_i}{d} \right \rceil \leqslant K + \sum_{i = 1}^{n} a_{i}$…

There are n people and k keys on a straight line. Every person wants to get to the office which is located on the line as well. To do that, he needs to reach some point with a key, take the key and then go to the office. Once a key is taken by somebo…

Vasily has a deck of cards consisting of n cards. There is an integer on each of the cards, this integer is between 1 and 100 000, inclusive. It is possible that some cards have the same integers on them. Vasily decided to sort the cards. To do this,…

Codeforces Round #423 (Div. 1, rated, based on VK Cup Finals) A.String Reconstruction B. High Load C. DNA Evolution 题意:给定一个只包含A,T,C,G的字符串S,有如下两种操作 1)修改一个点的字母. 2)给定一个字符串e ($\left | e \right |\leq 10$),生成一个由e重复组成的新串,eee...,问$S_{l..r}$中有几个字母跟这个新的字符串一一对应…

E. DNA Evolution 题目连接: http://codeforces.com/contest/828/problem/E Description Everyone knows that DNA strands consist of nucleotides. There are four types of nucleotides: "A", "T", "G", "C". A DNA strand is a seque…