当时晚上打CF时候比较晚,加上是集训期间的室友都没有晚上刷题的习惯,感觉这场CF很不在状态.A题写复杂WA了一发后去厕所洗了个脸冷静了下,换个简单写法,可是用cin加了ios::sync_with_stdio(false)还是WA了,真无语.B题读半天题,读懂后轻松A了,看了下比赛时间就快结束了,把C题读了一遍后,感觉能做,最后还是选择了睡觉23333.................. A题大意:平平平 增平减 ,缺任一都可,判断是否为这样的数列 #include<stdio.h> #inc…

http://codeforces.com/contest/831 A. Unimodal Array time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Array of integers is unimodal, if: it is strictly increasing in the beginning; after that…

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…

A:链接:http://codeforces.com/contest/831/problem/A 解题思路: 从前往后分别统计递增,相等,递减序列的长度,如果最后长度和原序列长度相等那么就输出yes: 实现代码: #include<bits/stdc++.h> using namespace std; int main() { ,a[]; cin>>m; ;i<m;i++){ cin>>a[i]; } ;i<m-;i++){ ]) ans++; else b…

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,…

Array of integers is unimodal, if: it is strictly increasing in the beginning; after that it is constant; after that it is strictly decreasing. The first block (increasing) and the last block (decreasing) may be absent. It is allowed that both of thi…

A. Unimodal Array time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Array of integers is unimodal, if: it is strictly increasing in the beginning; after that it is constant; after that it is…

题目链接:http://codeforces.com/contest/831/problem/D 题意:在一个一维坐标里,有n个人,k把钥匙(钥匙出现的位置不会重复并且对应位置只有一把钥匙),和一个终点p.问你每个人都拿到一把钥匙并且回到终点的情况下,n个人之中所花时间最长的那个人时间最少是多少?(一秒只能走一个单位的距离) 思路:考虑二分x,x为每个人能走的步数.对于两个人a,b和两把钥匙c,d 那么当p[a]<p[b]并且p[c]<p[d]时, a拿c钥匙,b拿d钥匙是最优的,因为对于p[…