OI road Treasure learning website / App Share

I want to become strong teenager? There are various sites I usually collect / App, they can help you find a better learning algorithm or problem-solving ideas. Ado, come open the door to stop the New World ~

Knowledge Learning

I find all kinds of obscure knowledge? There are a large number of algorithms explain, to help you better understand the principles of algorithms and implementation process, so that you handy in the actual process on these sites

OI-WIKI

OI Wiki is committed to being a free open and continuously updated knowledge integration site, you can get on programming competition (competitive programming) fun and practical knowledge here, we prepared a basic knowledge of the race for everyone, common questions, solution content topic and ideas and common tools to help you learn more quickly in-depth programming competition.

The content of this site is very complete in my opinion, constitutes a complete knowledge system, basically you want above algorithm can be found. While the interface is also very beautiful, comfortable to learn qwq. But there are fewer individual annotated entries, only the text to explain the principle of the need to rack their brains to understand.
Recommendation: ★★★★★

URL: https://oi-wiki.org/

VisuAlgo

VisuAlgo conceptualized by Dr. Steven Halim in 2011 as a tool to help his students a better understanding of data structures and algorithms, and let them learn at their own pace foundation.

Sorting algorithms, graph algorithms difficult to understand? It is the ultimate weapon you learn - it covers most of the bad algorithm described in words, and these algorithms to visualize, in the form of animation to show in front of us. This can help you be more thorough understanding of the algorithm and its principles, do not back you can easily use the template. But now the Chinese translation is not complete, and some text to explain the algorithm are still in English.
Recommendation: ★★★★★

URL: https://visualgo.net/zh

cplusplus.com

这里介绍的主要是C++的基本信息以及它的各种库、容器的参考文献（应该还会有其他的内容但我最常用的就是这个），它对绝大多数的STL都做了详尽的介绍，有具体的用法。问题是——这个网站是纯英文的QAQ，有点难啃。英语好的同学没事可以来探索探索。
推荐指数：★★★★

网址：http://www.cplusplus.com/

cppreference.com

这里介绍的是C++/C语言本身的语法以及其STL的使用。像是函数、类等概念都以简洁的形式讲解了，但……实在过于硬核。~~说实话自己没看懂~~
推荐指数：★★★

网址：https://zh.cppreference.com/

实用工具

在刷题的时候，难免会碰到一些毒瘤题目，怎么想也想不出来，这时候就需要借助一些工具啦。注意：不能滥用，应当培养自己独立思考的能力，毕竟竞赛中不会有这些神器的。

Graph Editor

在做图论题的时候总是免不了手动画图进行检验，这时候动手能力差的同学大多会得到一坨相互交叉缠绕的东西（比如我= =），严重影响做题体验。这时候就需要借助像这家网站这样的高科技玩意儿了XD。当你输入边、权值等数据时，它可以自动形成一个可拖动的、互不缠绕的图，没事的时候甚至可以建一条链拖着玩，~~这光滑的触感我可以玩一年。~~当然不知道是不是我个人原因，这个网站偶尔加载巨慢，甚至打不开……
推荐指数：★★★★★
P.S. 我们机房有大佬因为忘记网址做了个类似的离线版本（太强了%%%），这种精神值得学习orz

网址：https://csacademy.com/app/graph_editor/

The On-Line Encyclopedia of Integer Sequences(OEIS)

This is an integer sequence of search engines, such as when you "1,1,2,3,5,8", it will search for "Fibonacci number" and lists its recursive type and other information. So we have to deal with dead artifact qwq can not find the number of regular columns of the devil. But the most important thing is: You can not abuse, when you use this tool to solve a problem, you should remember that it contains several features columns, recursive, to ensure that the next encounter can do it.
Recommendation: ★★★★

URL: http://oeis.org/

geogebra

GeoGebra is free and cross-platform dynamic mathematics software offers all levels of education use, including geometry, algebra, tables, graphs, statistics and calculus in one easy to use software.

The APP is mainly used in the field of mathematics, but it's powerful, can solve some geometry, mathematical problems in OI (of course, there are certain limitations). You can use online, can download the installation package.
Recommendation: ★★★

URL / Download: https://www.geogebra.org/