This round of Div2 is easier than average. Every problem is not so complex. Most of them are thinking or implementation problem. Not hard, just have many small logics.
![](https://www.xloypaypa.pub/content/images/2021/04/image-9.png)
E. Almost Fault-Tolerant Database
It is a problem of thinking ability. Just consider the scenario of n=2 and extend it to other situations.
![](https://codeforces.org/s/88064/android-icon-192x192.png)
D. Genius's Gambit
Just a simple construction problem. The most complex part is not how to construct it but how to implement it after I know how to construct.
![](https://www.xloypaypa.pub/content/images/2021/04/image-8.png)
C. Maximum width
Solution
Greedy. Find the $p$ with the number as large as possible and $p'$ with number as small as possible.
The $p$ match from right to left, so that can make $p_i$ largest. Similarly, $p'$ match from left to right, so that can make $p'_i$ smallest. Then the maximum width is: $\max\limits_{{1}\leq{i}<{m}}{(p_{i+1}-p'_i)}$。
Code
![](https://codeforces.org/s/90002/images/codeforces-telegram-square.png)
The sample data and I are too weak. It can pass the sample data even I forgot read the input at all.
![](https://www.xloypaypa.pub/content/images/2021/04/image-7.png)
B. Card Deck
Solution
Greedy. Pick the card with maximum value from remain deck.
Because of the coefficient in front is $n^{n-1}$! Which is a very huge number.
Code
![](https://codeforces.org/s/88064/images/codeforces-telegram-square.png)
A. Three swimmers
Solution
Take remainder for everyone. If one of remainder is 0, then need 0 second. Otherwise original time minus reminder is the time needed to wait this person.
Code
![](https://codeforces.org/s/88064/images/codeforces-telegram-square.png)