Qingyu's blog

By Qingyu, history, 4 weeks ago, In English

Could not find an official announcement, let's discuss problems here.

Read more »

 
 
 
 
  • Vote: I like it
  • +117
  • Vote: I do not like it

By Qingyu, 6 weeks ago, In English

As we know, USACO is a competitive programming contest primarily for secondary school students in the US. It offers a large collection of excellent problems, from the easy to the difficult. Many of the problems are educational and worthwhile as training material.

However, the official website only offers problems from as early as 2011, and older problems are hard to find. Some of the Online Judges, such as POJ and BZOJ, contain some of the problems, but they are not properly filed together, and it's difficult to find the corresponding solution and test data.

In this post, I will try to list all the USACO materials that I have found so far. Most of the materials come from some old websites, and thanks to the efforts of web.archive.org, we can check out old websites that no longer exist. In addition, many of the problems were used as training materials in the training of Chinese IOI teams about 20 years ago. These materials have been preserved and are available through some Chinese websites.

It is important to note that since some of the materials are from a single source, I cannot confirm that the content is the original one. Also this list is not complete, there are still a lot materials I could not find. If anyone has these materials and would like to share it, please leave it in the comments section.

Update: Thanks to cjoa for providing some additional materials. They will be added to the list soon.

USACO 2020~2021

Spoiler

USACO 2019~2020

Spoiler

USACO 2018~2019

Spoiler

USACO 2017~2018

Spoiler

USACO 2016~2017

Spoiler

USACO 2015~2016

Spoiler

USACO 2014~2015

Spoiler

USACO 2013~2014

Spoiler

USACO 2012~2013

Spoiler

USACO 2011~2012

Spoiler

USACO 2010~2011

Spoiler

USACO 2009~2010

Spoiler

USACO 2008~2009

Spoiler

USACO 2007~2008

Spoiler

USACO 2006~2007

Spoiler

USACO 2005~2006

Spoiler

USACO 2004~2005

Spoiler

USACO 2003~2004

Spoiler

USACO 2002~2003

Spoiler

USACO 2001~2002

Spoiler

USACO 2000~2001

Spoiler

USACO 1999~2000

Spoiler

USACO 1998~1999

Spoiler

USACO 1997~1998

Spoiler

USACO 1996~1997

Spoiler

USACO 1992~1996

Spoiler

Read more »

 
 
 
 
  • Vote: I like it
  • +292
  • Vote: I do not like it

By Qingyu, history, 6 weeks ago, In English

Let's discuss problems here.

Read more »

 
 
 
 
  • Vote: I like it
  • +95
  • Vote: I do not like it

By Qingyu, history, 4 months ago, In English

The opentrains provides a series of high-quality ICPC training contests. However, its contest list is not complete(then it is difficult in finding some contests), and we cannot know if the contest has an editorial until we finish it. Therefore I made a list containing almost all of the contest materials, including contest id, statements, solutions and editorials. I don't know whether these materials can be made public (may affect their training value), so I only provided their corresponding links in opentrains in the table.

The link for Statements, Solutions and Editorials is in the format of http://opentrains.snarknews.info/~ejudge/index.cgi?solarc2=CONTEST_ID&sid=SESSION_ID. You can save the entire page and replace the field SID_HERE in the page with yours. Your SESSION_ID can be obtained from the URL that you jumped to after logging in at http://opentrains.snarknews.info.

For most of the Open Cup and Petrozavodsk contests, you can find the upsolve link in zimpha's posts(here and here). For other contests, I provided some upsolve links that do not require private logins.

You can find the list here, and I hope it will be helpful to you.

Read more »

 
 
 
 
  • Vote: I like it
  • +167
  • Vote: I do not like it

By Qingyu, history, 5 months ago, In English

GP of Beijing is finished now. How to solve H(Nonsense) and I(Number Theory)?

Read more »

 
 
 
 
  • Vote: I like it
  • +100
  • Vote: I do not like it

By Qingyu, history, 6 months ago, In English

How to solve B, H, K?

Read more »

 
 
 
 
  • Vote: I like it
  • +59
  • Vote: I do not like it