不想欠题了..... 多打打CF才知道自己智商不足啊... A. Vladik and flights 给你一个01串  相同之间随便飞 没有费用 不同的飞需要费用为  abs i-j 真是题意杀啊,,,实际上我们只考虑01转换的代价一定为1如果目的地和起点相同  费用为0 不相同  肯定为1  因为0旁边必然有1 #include <cstdio> #include <iostream> #include <algorithm> #include <vector…

A 题意:有n个机场处于一直线上,可两两到达,每个机场只可能属于两家公司中的一家(用0,1表示),现在要从a机场到b机场,可任意次转机.若机场i与机场j从属同一公司,则费用为0,否则费用为1.问最小费用? 分析:题目看懂就行了,起点和终点相同答案就是0,否则就是1 B 题意:和Wannafly Union Goodbye 2016的B题十分类似,分治搞 C 题意:求x,y,z使得对于给定的n(1≤n≤10^4) 2/n=1/x+1/y+1/z成立 分析:数学 目标是把2/n裂成3项 2/n=1/…

给出n个数字 1-8之间 要求选出来一个子序列 使里面1-8的数字个数 极差<=1 并且相同数字必须相邻(112 可以但是121不行)求这个子序列的最长长度 一道状压dp 看不懂别人的dp思想..自己造了一个出来.. 首先枚举t 意义是 当前选取子序列 每个数字最少是多少 那么这个子序列中的数字个数为t t+1 dp[i][j]当前在i位 选取数字的情况压缩成j 枚举没选过的数字 用前缀和进行二分查找 从第i位开始 求出res使在满足i-res这个区间有t或者t+1的某数字 进行转移 更新dp[…

E. Vladik and cards 题目链接 http://codeforces.com/contest/743/problem/E 题面 Vladik was bored on his way home and decided to play the following game. He took n cards and put them in a row in front of himself. Every card has a positive integer number not e…

D - Chloe and pleasant prizes 链接 http://codeforces.com/contest/743/problem/D 题面 Generous sponsors of the olympiad in which Chloe and Vladik took part allowed all the participants to choose a prize for them on their own. Christmas is coming, so sponso…

C. Vladik and fractions 题目链接 http://codeforces.com/contest/743/problem/C 题面 Vladik and Chloe decided to determine who of them is better at math. Vladik claimed that for any positive integer n he can represent fraction as a sum of three distinct posit…

B. Chloe and the sequence 题目链接 http://codeforces.com/contest/743/problem/B 题面 Chloe, the same as Vladik, is a competitive programmer. She didn't have any problems to get to the olympiad like Vladik, but she was confused by the task proposed on the ol…

A. Vladik and flights 题目链接 http://codeforces.com/contest/743/problem/A 题面 Vladik is a competitive programmer. This year he is going to win the International Olympiad in Informatics. But it is not as easy as it sounds: the question Vladik face now is…

传送门 Description Vladik and Chloe decided to determine who of them is better at math. Vladik claimed that for any positive integer n he can represent fraction   as a sum of three distinct positive fractions in form . Help Vladik with that, i.e for a g…

传送门 Description Chloe, the same as Vladik, is a competitive programmer. She didn't have any problems to get to the olympiad like Vladik, but she was confused by the task proposed on the olympiad. Let's consider the following algorithm of generating a…