Odd that we find definitions definitive. http://www.stevekrenzel.com/ en-us Copyright 2010 Steve Krenzel When I took the GREs it reminded me of something I was told when I worked at Google: Larry and Sergey used to hire based on a formula using the SATs and GPAs. They considered the SAT an applicant's po... http://www.stevekrenzel.com/articles/gres-and-google http://www.stevekrenzel.com/articles/gres-and-google Wed Feb 17 22:38:02 2010 Here is an extremely simple implementation of a statistical full text substring search which has a runtime independent of the corpus size. Recall is 100% and precision is adjustable. We use the sample... http://www.stevekrenzel.com/articles/simple-statistical-substring-searching http://www.stevekrenzel.com/articles/simple-statistical-substring-searching Thu Feb 18 00:00:41 2010 The University of Melbourne concluded that allowing employees to spend time on personal affairs during the work day boosts productivity by up to 9%. This is something that those of us in the software ... http://www.stevekrenzel.com/articles/goofing-off-at-work http://www.stevekrenzel.com/articles/goofing-off-at-work Thu Feb 18 00:19:25 2010 Sometimes when debugging trees it's useful to analyze them by printing them out. Using a reversed inorder traversal makes this easy. Using the code below you'll get something like this: 14... http://www.stevekrenzel.com/articles/printing-trees http://www.stevekrenzel.com/articles/printing-trees Sat Feb 20 18:09:34 2010 I took the GREs recently with about a week and a half of prep. I arguably did pretty well (above the average score for masters and phd students in the Ivy League). Here are 8 quick rules to remember t... http://www.stevekrenzel.com/articles/gres http://www.stevekrenzel.com/articles/gres Sat Feb 20 18:33:08 2010 About a year ago our flight was delayed coming back from a business trip in California. Really delayed, as in minutes before we were about to board some observant technician noticed that one of our en... http://www.stevekrenzel.com/articles/power-of-nice http://www.stevekrenzel.com/articles/power-of-nice Sun Feb 21 00:23:08 2010 We all have our off days, they're particularly memorable when they coincide with the day of an interview. One of my fondest interviewing memories is from right before I had graduated from my undergrad... http://www.stevekrenzel.com/articles/20000-sloc http://www.stevekrenzel.com/articles/20000-sloc Sun Feb 21 00:55:49 2010 MapReduce is a framework originally developed at Google that allows for easy large scale distributed computing across a number of domains. Apache Hadoop is an open source implementation. I'll gloss ov... http://www.stevekrenzel.com/articles/finding-friends http://www.stevekrenzel.com/articles/finding-friends Sun Feb 21 01:08:32 2010 A study from the University of Melbourne concluded that allowing employees to spend time on personal affairs during the work day boosts productivity by up to 9%. This is something that those of us in ... http://www.stevekrenzel.com/articles/goofing-off http://www.stevekrenzel.com/articles/goofing-off Tue Feb 23 00:16:28 2010 There was a good post on proggit the other day about optimizing code and making the final code 80 to 100 times faster than the original. The task was: Given a list of words, and two words from that li... http://www.stevekrenzel.com/articles/without-the-n http://www.stevekrenzel.com/articles/without-the-n Wed Feb 24 22:00:07 2010 I recently submitted a python solution to the Kember Identity Project. I wasn't striving for speed, but rather clarity, simply because the first implementation that was up was fairly convoluted (with ... http://www.stevekrenzel.com/articles/md5-cycles http://www.stevekrenzel.com/articles/md5-cycles Thu Feb 25 00:46:26 2010 There was a CL post making rounds earlier about writing the most "wicked" hello world program. Here is my response: r,e,a,l = range,enumerate,all,0 for i,x in e(i for i in r(4,10**4) if a(i%... http://www.stevekrenzel.com/articles/obnoxious-ninja http://www.stevekrenzel.com/articles/obnoxious-ninja Sun Feb 28 01:25:25 2010 This past month has been crazy. I was in Orlando for a week for a conference, then me and my girlfriend went to Disney World for a week. We flew back from Disney on a Monday night, went to sleep and t... http://www.stevekrenzel.com/articles/interesting-month http://www.stevekrenzel.com/articles/interesting-month Sun Feb 28 01:27:18 2010 The Google Code Jam qualifying round was a few days ago and I thought it'd be fun to go over the three solutions that I came up with. I didn't actually compete, this was just done on my own time for f... http://www.stevekrenzel.com/articles/pareto http://www.stevekrenzel.com/articles/pareto Sun Feb 28 02:30:17 2010 This challenge was the easiest and should have taken most people just a few minutes. You're given a list of words that define a language, and then a list of patterns that should represent a word in th... http://www.stevekrenzel.com/articles/alien-language http://www.stevekrenzel.com/articles/alien-language Sun Feb 28 02:33:14 2010 This challenge by far involved the most code. The problem is: You're given a topology and need to determine how water will flow on it. When you calculate where each point of water will flow, you also ... http://www.stevekrenzel.com/articles/watersheds http://www.stevekrenzel.com/articles/watersheds Sun Feb 28 02:37:31 2010 This challenge was my favorite one, it was the only one of the three challenges that forced me to go back and rethink my solution after it worked on the small data set but not the larger one. The goal... http://www.stevekrenzel.com/articles/welcome_to_code_jam http://www.stevekrenzel.com/articles/welcome_to_code_jam Sun Feb 28 02:53:16 2010 I was reading a usenet thread from 1985. The topic of discussion was if there will be a problem with computers in the year 2000 (now known as the y2k bug). One person chimed in that they had already h... http://www.stevekrenzel.com/articles/stepwise_interactive_development http://www.stevekrenzel.com/articles/stepwise_interactive_development Sun Feb 28 02:56:27 2010 I have to admit, I'm a little confused at all of the coverage of a recent paper. You can read some of the coverage at these places: Slashdot PyEvolve PhysOrg O' Reilly The paper is titled "Th... http://www.stevekrenzel.com/articles/benfords-law http://www.stevekrenzel.com/articles/benfords-law Tue Mar 2 02:14:40 2010 Suppose you ran a search engine and someone searched for a three word phrase like "cheap pudding pops". Also suppose you've already solved the problem of finding relevant URLs. The problem y... http://www.stevekrenzel.com/articles/blurbs http://www.stevekrenzel.com/articles/blurbs Tue Mar 2 02:15:43 2010 One of the common methods for calculating fibonacci numbers quickly involves matrix exponentiation. I recently came across a new algorithm for generating Fibonacci numbers by Japanese mathematician Ta... http://www.stevekrenzel.com/articles/fibonacci http://www.stevekrenzel.com/articles/fibonacci Tue Mar 2 02:15:57 2010 I was asked about finding the longest palindrome in a string today. Here is how I said I'd approach the problem. Algorithm: Assume for simplicity that the palindrome is a length that is an odd number.... http://www.stevekrenzel.com/articles/longest-palnidrome http://www.stevekrenzel.com/articles/longest-palnidrome Tue Mar 2 02:16:03 2010 In my previous post on statistical substring searching I mentioned that I'd follow up with some stats on it's accuracy. Here they are. To generate the "results accuracy" plot, I generated ev... http://www.stevekrenzel.com/articles/statistical-substring-searching-stats http://www.stevekrenzel.com/articles/statistical-substring-searching-stats Tue Mar 2 02:16:09 2010 This is a post about HashFold, a theoretical framework (for now) that is suited to performing the same types of distributed computation that MapReduce can perform, but improves upon MapReduce both in ... http://www.stevekrenzel.com/articles/hashfold http://www.stevekrenzel.com/articles/hashfold Thu Mar 4 02:42:34 2010 I've been working on a project which implements a number of data structures in Python that are stored entirely on disk. It started when I needed data structures that were gigabytes in size, but I only... http://www.stevekrenzel.com/articles/dynamic-arrays-no-copy http://www.stevekrenzel.com/articles/dynamic-arrays-no-copy Tue Mar 16 02:16:58 2010 This post is about applying to graduate school, specifically writing the statement of purpose. I was recently accepted to Cornell and thought my experience could be helpful to others. The statement o... http://www.stevekrenzel.com/articles/statement-of-purpose http://www.stevekrenzel.com/articles/statement-of-purpose Sun Mar 28 14:24:50 2010 I've been doing a lot of programming using Tornado recently, but my one complaint is that its autoreloading is really broken. When I change a file, I want the server to restart without me needing to d... http://www.stevekrenzel.com/articles/autoreload http://www.stevekrenzel.com/articles/autoreload Sun Jul 11 01:19:57 2010 Newton's method is a popular algorithm for calculating the square root of a number, however, it's easy to forget how to implement it. We can fix that by taking an algorithm that any computer scientis... http://www.stevekrenzel.com/articles/newtons-law http://www.stevekrenzel.com/articles/newtons-law Mon Mar 7 02:27:48 2011 For those of you who don't know, I've been working on a new company for the past few months called Thinkfuse with two co-founders of mine. We've put together an amazing team of investors, which are me... http://www.stevekrenzel.com/articles/hiring http://www.stevekrenzel.com/articles/hiring Wed Mar 30 00:39:34 2011 A couple of weeks ago Instagram wrote a blog post about taking an image that has been shredded into slices and rearranging the slices to reconstruct the original image. I wrote up a solution in coffee... http://www.stevekrenzel.com/articles/instagram http://www.stevekrenzel.com/articles/instagram Wed Dec 21 04:22:17 2011