D. Dreamoon and Sets time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Dreamoon likes to play with sets, integers and .  is defined as the largest positive integer that divides both a and b.…

B. Dreamoon and WiFi time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Dreamoon is standing at the position 0 on a number line. Drazil is sending a list of commands through Wi-Fi to Dreamoon'…

A. Dreamoon and Stairs time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Dreamoon wants to climb up a stair of n steps. He can climb 1 or 2 steps at each move. Dreamoon wants the number of mo…

E. Dreamoon and Strings time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Dreamoon has a string s and a pattern string p. He first removes exactly x characters from s obtaining string s' as a…

Codeforces Round #272 (Div. 2) A. Dreamoon and Stairs time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Dreamoon wants to climb up a stair of n steps. He can climb 1 or 2 steps at each move.…

D. Dreamoon and Sets 题目连接: http://www.codeforces.com/contest/476/problem/D Description Dreamoon likes to play with sets, integers and . is defined as the largest positive integer that divides both a and b. Let S be a set of exactly four distinct inte…

D. Dreamoon and Sets   Dreamoon likes to play with sets, integers and .  is defined as the largest positive integer that divides both a and b. Let S be a set of exactly four distinct integers greater than 0. Define S to be of rank k if and only if fo…

A. Dreamoon and Stairs time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Dreamoon wants to climb up a stair of n steps. He can climb 1 or 2 steps at each move. Dreamoon wants the number of mo…

题意与分析 (CodeForces 617C) 题意是这样的:一个花圃中有若干花和两个喷泉,你可以调节水的压力使得两个喷泉各自分别以\(r_1\)和\(r_2\)为最远距离向外喷水.你需要调整\(r_1,r_2\)的值使得所有的花都能被水所灌溉--换句话说,每一朵花要么到第一个喷泉的距离不超过\(r_1\),要么到第二个喷泉的距离不超过\(r_2\).当然如果两个条件都满足也是可以的.你需要用尽可能少的水来实现以上要求,也就是说使得\(r_1^2+r_2^2\)尽可能的小.找出这个最小值. 那么…

题意与分析 (CodeForces - 603A) 这题真的做的我头疼的不得了,各种构造样例去分析性质... 题意是这样的:给出01字符串.可以在这个字符串中选择一个起点和一个终点使得这个连续区间内所有的位取反.求经过处理后最多会得到多少次01变换(可以不连续). 首先求原串的最长01长度,这个太简单了,然后才是重头戏:精彩的构造样例分类讨论环节--如何增加01的最长串? 我们考虑一下反转串的几种情况:1.反转单个连续0/1串的内部:2.反转两个部分连续0/1串与中间的内容(内部无连续串)3.反…