Qingyu's blog

By Qingyu, history, 4 months ago, In English

How to solve task C and G?

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By Qingyu, history, 6 months ago, In English

Since I didn't find a place to discuss the CCO problems, I decided to post this blog.

How to solve Day 2 Problem 3 (Good Game)?

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By Qingyu, history, 6 months ago, In English

Let's discuss the problems here.

How to solve H. (Hoshi Sudoku) and I. (Imbalance)?

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By Qingyu, history, 7 months ago, In English

Let's discuss the tasks here.

How to solve problem B?

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By Qingyu, history, 7 months ago, In English

It seems that the Baltic Olympiad in Informatics (BOI) 2022 is taking place.

Since I didn't find any announcement, will there be a mirror contest this year?

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By Qingyu, history, 9 months ago, In English

Let's discuss problems here.

How did you solve problem L?

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By Qingyu, history, 13 months ago, In English

How to solve Problem 7, 10? Is there any tutorial available?

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By Qingyu, history, 14 months ago, In English

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

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By Qingyu, 15 months 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, 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.

USACO 2021~2022

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USACO 2020~2021

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USACO 2019~2020

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USACO 2018~2019

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USACO 2017~2018

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USACO 2016~2017

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USACO 2015~2016

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USACO 2014~2015

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USACO 2013~2014

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USACO 2012~2013

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USACO 2011~2012

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USACO 2010~2011

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USACO 2009~2010

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USACO 2008~2009

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USACO 2007~2008

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USACO 2006~2007

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USACO 2005~2006

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USACO 2004~2005

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USACO 2003~2004

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USACO 2002~2003

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USACO 2001~2002

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USACO 2000~2001

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USACO 1999~2000

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USACO 1998~1999

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USACO 1997~1998

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USACO 1996~1997

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USACO 1992~1996

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By Qingyu, history, 15 months ago, In English

Let's discuss problems here.

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By Qingyu, history, 17 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.

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By Qingyu, history, 18 months ago, In English

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

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By Qingyu, history, 19 months ago, In English

How to solve B, H, K?

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