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Seo Master present to you: Back-to-School usually means preparing new courses and topics. Educators as well as students are looking for exciting and fresh content. We are happy to announce that we are able to share some new additions to Google Code University's repository of CS course materials just in time for the fall semester. As always, all of these course materials are Creative Commons licensed and can be reused and adapted to curricula at universities everywhere:

• University of Southern California: Exercises on AJAX Programming
• California Polytechnic State University: Lectures and lab exercises on Distributed Systems
• University of Washington: Assignments on Distributed Systems

Please also check out our CS Resources page for updates on useful training materials.

But that's not all! We want to encourage educators to contribute their great content to Google Code University. By implementing a submission form we hope to make the process easy and convenient. Just follow the big blue button on the homepage and tell us about your materials. We look forward to hearing from you!

By Andrea Held, Google Code University Team2013, By: Seo Master

Seo Master present to you: Given a 49x49 grid of numbers, can you place mines in the cells in such a way that each number represents the number of mines in its 3x3 sub-grid (the cell itself and its 8 immediate neighbors)? Find the maximum number of mines that could end up in the middle row of the grid.

Intrigued? Think you can solve it with a clever algorithm? Here at Google, we know how thrilling it can be to encounter a challenge and then overcome it by coding up a creative solution. Since 2003, we've been privileged to share that experience with a global community of computer programmers through our annual programming competition, Google Code Jam.

We're excited to announce Google Code Jam 2009, powered by Google App Engine. Join the fun and compete in several 2½-hour online rounds, attacking three to four difficult algorithmic problems during each round. You may use your favorite programming languages and tools to code up a solution. When ready, run your solution against our fiendish test data. The algorithm needs to be right, and it needs to be efficient: when N=10000, O(N³) won't cut it!

If you're up to the challenge, visit the Google Code Jam site to register and read the rules. Most importantly, you can practice on the problems from last year's contest, so you are in shape when the qualification round starts on September 2. You could be one of the top 25 competitors who will be flown to our Mountain View headquarters to match wits for the $5,000 first prize, and the title of Code Jam champion!

P.S. Think you can solve our "Mine Layer" problem? Try it out on the Code Jam website!

By Igor Naverniouk, Code Jam Team2013, By: Seo Master

Seo Master present to you:
By Bartholomew Furrow, Software Engineer

In Mountain View and in offices around the world, Googlers are spending their 20% time to get ready for Google Code Jam 2011, preparing algorithmic problems for the 10,000 or more contestants who we expect to compete in our Qualification Round this Friday.

A good Code Jam problem has a story to ground it in some version of reality: soccer, ninja and messages from alien cultures have all served admirably. Cushioned by the story, the core of a Code Jam problem is an algorithmic puzzle whose solution needs anything from a few lines of code to a deep understanding of flow algorithms or number theory.


Anyone at Google can create Code Jam problems, which means that our methods for inventing them vary wildly. One author might come across a real-life situation, think about what algorithm would solve it, and base a problem on that; another author might think about how to make a problem out of a video game. Sometimes a problem author will start with an algorithm and concoct a problem that it solves. We also really seem to like inventing weird situations on chess boards.

With the story and the problem chosen, our work is only partly done. The problem has to be stated in such a way that it will be clear, even for an audience from 125 countries. At least three engineers work on each problem’s statement: that group includes at least one native English speaker to make sure the grammar is all correct, and at least one non-native English speaker to make sure the language is clear enough.

The toughest part about setting up a problem like this is verifying that contestants got it right. In Code Jam, we do that by providing contestants with an input file full of test data. They send back their program’s output, which should be the answer to the input file’s question. The hard part is deciding what goes in that input file: we need edge cases, plenty of average cases, and a good number of cases that make sure the contestant’s code is fast enough. To create all of those, we generate some cases by hand and others pseudo-randomly. We’ve been known to generate a test case or two out of ASCII art, or as a creative-writing exercise.

Finally, we solve the problems ourselves. We require at least three solutions made by different engineers, and sometimes we have those engineers write solutions that we know to be wrong – just to make sure our test data catches them out.

The end result of this process is the kind of problem we’re proud to ask our contestants to solve. In 2011 more than any other year, we’re excited about the creativity of our colleagues and the problems we’re planning to pose. We hope you’ll enjoy the problems from the other side – and if you’re a great software engineer, maybe come help us write them in 2012.

You can register for Google Code Jam 2011 at http://code.google.com/codejam, and you’ll see the first problems of the year in the Qualification Round this Friday, May 6, starting at 23:00 UTC. For even more details about how we get problems ready for Code Jam, you can read our official problem-preparation guide.


Bartholomew Furrow spends 80% of his time at Google finding ways to eliminate bad search ads, and the rest on Code Jam. Programming contests introduced him to Computer Science, to Google, and to his wife.

Posted by Scott Knaster, Editor

2013, By: Seo Master

Seo Master present to you:
By Igor Naverniouk, Software Engineer, Code Jam

Last Friday, we kicked off our Code Jam qualification round where over 36,000 programmers from around the world competed for a chance to be one of the 25 finalists invited to New York for the final showdown. While registration for Code Jam is now closed, we didn’t want to keep you waiting a whole year to re-try your luck.


Starting tomorrow, April 19 at 7:00 AM PDT / 14:00 UTC, we will be running a Code Jam sprint. The stakes, you ask? The 100 top scoring developers to solve at least one two-part challenge will be given the opportunity to purchase tickets to Google I/O, which sold out in just over 20 minutes this year.

You don’t have to be a seasoned Code Jam veteran to participate, but you’ll want to register in advance. This ensures that the only thing between you and your ticket to Google I/O is a single challenge and a few quick clicks. In case you want a warm up, check out our Code Jam quick-start guide and practice questions.

The URL for the challenge will be posted to our +Google Developers page promptly tomorrow, April 19 at 7:00 AM, so don’t miss your chance to code your way to Google I/O this year!


Update 9:20 PM: We've edited this post to clarify exactly how the successful entries will be determined. Please read the bold sentence above for details.


Code Jam is a worldwide programming competition in which contestants may use any programming language to solve algorithmic problems. Although registration for Code Jam 2012 is now closed, developers can still compete in our Sprint to Google I/O for a chance to purchase a ticket to the conference for $900.


As his main job, Igor Naverniouk builds analytics for Google Play. In his 20% time, he works on programming challenges for Code Jam.

Posted by Scott Knaster, Editor

2013, By: Seo Master