A. Vladik and flights time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Vladik is a competitive programmer. This year he is going to win the International Olympiad in Informatics. But it is…

思路: dfs序其实是很水的东西.  和树链剖分一样, 都是对树链的hash. 该题做法是:每次对子树全部赋值为1,对一个点赋值为0,查询子树最小值. 该题需要注意的是:当我们对一棵子树全都赋值为1的时候, 我们要查询一下赋值前子树最小值是不是0, 如果是的话, 要让该子树父节点变成0, 否则变0的信息会丢失. 细节参见代码: #include <cstdio> #include <cstring> #include <algorithm> #include <i…

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…

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/…

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…