soda has a set $S$ with $n$ integers ${1, 2, dots, n}$. A set is called key set if the sum of integers in the set is an even number. He wants to know how man...

Today, Wet Shark is given n integers. Using any of these integers no more than once, Wet Shark wants to get maximum possible even (divisible by 2) sum. Please, ...

http://codeforces.com/contest/738/problem/C

http://acm.hust.edu.cn/vjudge/contest/view.action?cid=102271#problem/ADescriptionCarl is a beginne

SmallR is an archer. SmallR is taking a match of archer with Zanoes. They try to shoot in the target in turns, and SmallR shoots first. The probability of shoot...

题目描述： In an episode of the Dick Van Dyke show, little Richie connects the freckles on his Dad’s back to form a picture of the Liberty Bell. Alas, one of t...

While playing with geometric figures Alex has accidentally invented a concept of a nn-th order rhombus in a cell grid.

You are playing a variation of game 2048. Initially you have a multiset ss of nn integers. Every integer in this multiset is a power of two.

----简单的权限（拦截）管理给特定的用户以不同的权限来访问不同的资源很多人把权限模型理解为 用户—权限，这样不是不可以，是不够好。因为如果有100个用户，20个权限呢？给每个用户单独一个个设置...

Django的filter查询name__contains表示精确大小写的模糊查询使用name__icontains表示忽略大小写year_count = DownloadFile.objects.filter(date__contains='2018').count()year_up_rate=round((......