<rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>Hacker News: Mgccl</title><link>https://news.ycombinator.com/user?id=Mgccl</link><description>Hacker News RSS</description><docs>https://hnrss.org/</docs><generator>hnrss v2.1.1</generator><lastBuildDate>Thu, 11 Jun 2026 03:47:50 +0000</lastBuildDate><atom:link href="https://hnrss.org/user?id=Mgccl" rel="self" type="application/rss+xml"></atom:link><item><title><![CDATA[New comment by Mgccl in "Utilities puzzle mug"]]></title><description><![CDATA[
<p>Yes. K_{3,3} can be embedded on a torus.</p>
]]></description><pubDate>Sat, 16 Nov 2013 19:47:16 +0000</pubDate><link>https://news.ycombinator.com/item?id=6746178</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=6746178</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=6746178</guid></item><item><title><![CDATA[New comment by Mgccl in "Ph.D. 2.0: Rethinking the Ph.D. Application"]]></title><description><![CDATA[
<p>Theory cs could care less about coding abilities. It's never a bad thing to know how to code, but I can go though the entire PhD program without coding a single line of code. (Well not really, one of the professors in my PhD program committee recommended me to do one systems course. other than that, I just prove theorems. )</p>
]]></description><pubDate>Thu, 14 Nov 2013 19:30:23 +0000</pubDate><link>https://news.ycombinator.com/item?id=6734853</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=6734853</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=6734853</guid></item><item><title><![CDATA[New comment by Mgccl in "Ph.D. 2.0: Rethinking the Ph.D. Application"]]></title><description><![CDATA[
<p>It's hard for someone in anything remote to math/science without coding anything in their entire undergraduate life.<p>It's like you say no one can be admitted to a PhD program in US without first learning some English.</p>
]]></description><pubDate>Thu, 14 Nov 2013 19:09:09 +0000</pubDate><link>https://news.ycombinator.com/item?id=6734655</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=6734655</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=6734655</guid></item><item><title><![CDATA[New comment by Mgccl in "100% Compression Using Pi"]]></title><description><![CDATA[
<p>1. There is no proof that pi is a normal number.
2. The index of the position takes up space.</p>
]]></description><pubDate>Fri, 08 Nov 2013 20:37:41 +0000</pubDate><link>https://news.ycombinator.com/item?id=6698971</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=6698971</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=6698971</guid></item><item><title><![CDATA[New comment by Mgccl in "A Dig Through Old Files Reminds Me Why I’m So Critical of Science"]]></title><description><![CDATA[
<p>mathematician make errors. I want something that can be checked formally.</p>
]]></description><pubDate>Mon, 04 Nov 2013 21:28:13 +0000</pubDate><link>https://news.ycombinator.com/item?id=6671307</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=6671307</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=6671307</guid></item><item><title><![CDATA[New comment by Mgccl in "A Dig Through Old Files Reminds Me Why I’m So Critical of Science"]]></title><description><![CDATA[
<p>This is why I think it be important to have a language designed to express algorithms and can be verified of correctness to a certain point.</p>
]]></description><pubDate>Sun, 03 Nov 2013 21:54:16 +0000</pubDate><link>https://news.ycombinator.com/item?id=6665283</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=6665283</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=6665283</guid></item><item><title><![CDATA[New comment by Mgccl in "Dear Startups: stop asking me math puzzles to figure out if I can code"]]></title><description><![CDATA[
<p>I haven't done any statistical surveys, in my undergrad years, I find math students are much smarter than the cs majors.</p>
]]></description><pubDate>Mon, 21 Oct 2013 07:33:19 +0000</pubDate><link>https://news.ycombinator.com/item?id=6583917</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=6583917</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=6583917</guid></item><item><title><![CDATA[New comment by Mgccl in "What are the math heavy CS areas with high demand?"]]></title><description><![CDATA[
<p>Why do you care about the high demand? We can put that aside for now--if you are a competent coder, you are in high demand...<p>If you want to have more math, then some subfield in CS theory is the way to go.
CS theory have lot of elegant math. complexity, data structure, algorithms, combinatorial optimization, computational geometry. All of them have nice set of mathematical tools you can use. There are also unexpected ones that uses more traditional mathematics, like universal algebra for CSP, functional analysis in graph embedding with little distortion, and topology for computational topology(well that seems obvious, there are certain uses for computational topology, read up on persistent topology, which I guess is part of machine learning now).<p>Of course, the demands are low for pure theory students. However you can do some practical work. For example <a href="http://www.tokutek.com/" rel="nofollow">http://www.tokutek.com/</a> , founded by professors who specialize in cache oblivious data structures. Some more practical ones include cache oblivious data structures, sublinear time algorithms, string related algorithms. In Google, there are researchers working on how to optimize ads.<p>Also, I just don't see how you are going to write non-boilerplate code anywhere. everything eventually become repetitive(unless you use Haskell, anything new become a paper.)</p>
]]></description><pubDate>Sun, 06 Oct 2013 05:59:28 +0000</pubDate><link>https://news.ycombinator.com/item?id=6503306</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=6503306</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=6503306</guid></item><item><title><![CDATA[New comment by Mgccl in "How to Advertise on a Porn Website"]]></title><description><![CDATA[
<p>It could mean "2/3 of the men who took the survey admit to watching porn" for w/e survey they had in mind...</p>
]]></description><pubDate>Tue, 10 Sep 2013 16:42:18 +0000</pubDate><link>https://news.ycombinator.com/item?id=6361188</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=6361188</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=6361188</guid></item><item><title><![CDATA[New comment by Mgccl in "School is a prison and damaging our kids"]]></title><description><![CDATA[
<p>How about "Math beyond arithmetic is not important at all for the vast majority of adults today."</p>
]]></description><pubDate>Thu, 05 Sep 2013 01:08:22 +0000</pubDate><link>https://news.ycombinator.com/item?id=6331584</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=6331584</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=6331584</guid></item><item><title><![CDATA[More algorithms on perfectly balanced photo gallery]]></title><description><![CDATA[
<p>Article URL: <a href="http://www.chaoxuprime.com/posts/2013-08-16-more-algorithms-on-perfectly-balanced-photo-gallery.html">http://www.chaoxuprime.com/posts/2013-08-16-more-algorithms-on-perfectly-balanced-photo-gallery.html</a></p>
<p>Comments URL: <a href="https://news.ycombinator.com/item?id=6223168">https://news.ycombinator.com/item?id=6223168</a></p>
<p>Points: 1</p>
<p># Comments: 0</p>
]]></description><pubDate>Fri, 16 Aug 2013 10:31:11 +0000</pubDate><link>http://www.chaoxuprime.com/posts/2013-08-16-more-algorithms-on-perfectly-balanced-photo-gallery.html</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=6223168</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=6223168</guid></item><item><title><![CDATA[New comment by Mgccl in "The algorithm for a perfectly balanced photo gallery"]]></title><description><![CDATA[
<p>See the updated content in the link and the code in here <a href="http://www.chaoxuprime.com/posts/2013-08-16-more-algorithms-on-perfectly-balanced-photo-gallery.html" rel="nofollow">http://www.chaoxuprime.com/posts/2013-08-16-more-algorithms-...</a>
Both in Haskell. you can see how to implement it from scratch...</p>
]]></description><pubDate>Fri, 16 Aug 2013 10:16:15 +0000</pubDate><link>https://news.ycombinator.com/item?id=6223132</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=6223132</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=6223132</guid></item><item><title><![CDATA[New comment by Mgccl in "Searching a Sorted Matrix Faster"]]></title><description><![CDATA[
<p>This is a common technique of switching between two algorithms. iirc, I never saw this as an material in undergrad algorithms course.<p>I wrote on another problem that uses this technique. Mix ternary search and linear search to find the minima of an first decreasing then increasing array.<p><a href="http://www.chaoxuprime.com/posts/2013-07-27-find-the-minimum-of-an-array.html" rel="nofollow">http://www.chaoxuprime.com/posts/2013-07-27-find-the-minimum...</a></p>
]]></description><pubDate>Wed, 14 Aug 2013 00:55:01 +0000</pubDate><link>https://news.ycombinator.com/item?id=6209346</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=6209346</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=6209346</guid></item><item><title><![CDATA[New comment by Mgccl in "frak: Transform collections of strings into regular expressions"]]></title><description><![CDATA[
<p>Google Analytics has a filter system that allow one to use regular expressions of length at most 255.<p>Sometimes, people have long list of strings that have total length more than 255 characters. frak would be a nice tool for compression.</p>
]]></description><pubDate>Tue, 13 Aug 2013 05:59:55 +0000</pubDate><link>https://news.ycombinator.com/item?id=6204234</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=6204234</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=6204234</guid></item><item><title><![CDATA[New comment by Mgccl in "The algorithm for a perfectly balanced photo gallery"]]></title><description><![CDATA[
<p>Since I'm a CS theory person, I can offer some theoretical improvements on the running time and make the problem even more general...<p>Instead of minimize the linear difference of partition, we might want to minimize the standard deviation, or basically any convex function, and still do it in the same time bound.<p>One can reduce this problem to find a k-edge path of minimum weight on a complete DAG. The naive algorithm will run in O(kn^2), but we can improve the running time to O(kn) by realize the weight on this DAG has the Monge property. This is very practical to implement.<p>I posed it as a problem on daily haskell exercise <a href="http://dailyhaskellexercise.tumblr.com/post/58060450750/the-minimum-weight-path-of-length-k-in-a-dag-with" rel="nofollow">http://dailyhaskellexercise.tumblr.com/post/58060450750/the-...</a>.<p>In this application, k is very large. n is just a constant multiple of k. We can use a <i>theoretically</i> better algorithm that takes n2^O(sqrt(log n loglog n)) time. (this is almost O(n^(3/2))). I doubt it will ever be implemented with speed comparible to the O(kn) solution. See <a href="http://www.cs.ust.hk/mjg_lib/bibs/DPSu/DPSu.Files/sdarticle_204.pdf" rel="nofollow">http://www.cs.ust.hk/mjg_lib/bibs/DPSu/DPSu.Files/sdarticle_...</a><p>I shall post a solution tomorrow since I'm currently touring NYC with my gf...</p>
]]></description><pubDate>Mon, 12 Aug 2013 14:53:23 +0000</pubDate><link>https://news.ycombinator.com/item?id=6199513</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=6199513</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=6199513</guid></item><item><title><![CDATA[Daily Haskell Exercise]]></title><description><![CDATA[
<p>Article URL: <a href="http://dailyhaskellexercise.tumblr.com/">http://dailyhaskellexercise.tumblr.com/</a></p>
<p>Comments URL: <a href="https://news.ycombinator.com/item?id=6191901">https://news.ycombinator.com/item?id=6191901</a></p>
<p>Points: 2</p>
<p># Comments: 0</p>
]]></description><pubDate>Sat, 10 Aug 2013 17:32:04 +0000</pubDate><link>http://dailyhaskellexercise.tumblr.com/</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=6191901</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=6191901</guid></item><item><title><![CDATA[Find the minimum of a decreasing then increasing array]]></title><description><![CDATA[
<p>Article URL: <a href="http://www.chaoxuprime.com/posts/2013-07-27-find-the-minimum-of-an-array.html">http://www.chaoxuprime.com/posts/2013-07-27-find-the-minimum-of-an-array.html</a></p>
<p>Comments URL: <a href="https://news.ycombinator.com/item?id=6112522">https://news.ycombinator.com/item?id=6112522</a></p>
<p>Points: 1</p>
<p># Comments: 0</p>
]]></description><pubDate>Sat, 27 Jul 2013 11:17:24 +0000</pubDate><link>http://www.chaoxuprime.com/posts/2013-07-27-find-the-minimum-of-an-array.html</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=6112522</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=6112522</guid></item><item><title><![CDATA[New comment by Mgccl in "Fun with Prolog: Priceonomics Puzzle"]]></title><description><![CDATA[
<p>I thought you would want the most negative cycle, which would be NP-hard to find.</p>
]]></description><pubDate>Sat, 08 Jun 2013 08:01:20 +0000</pubDate><link>https://news.ycombinator.com/item?id=5844289</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=5844289</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=5844289</guid></item><item><title><![CDATA[New comment by Mgccl in "Fun with Prolog: Priceonomics Puzzle"]]></title><description><![CDATA[
<p>Let's put some algebra/order into this...
Bellman-Ford works for any totally ordered group (G,+), such that a+b<=a+c if b<=c.<p>What logarithm does is just a order preserving homomorphism from (R,*) to (R,+).</p>
]]></description><pubDate>Sat, 08 Jun 2013 08:00:22 +0000</pubDate><link>https://news.ycombinator.com/item?id=5844287</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=5844287</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=5844287</guid></item><item><title><![CDATA[New comment by Mgccl in "B-Heap vs. Binary Heap (2010)"]]></title><description><![CDATA[
<p>true.<p>irrc there is only a constant factor of time difference between the two.</p>
]]></description><pubDate>Tue, 23 Apr 2013 00:50:16 +0000</pubDate><link>https://news.ycombinator.com/item?id=5592643</link><dc:creator>Mgccl</dc:creator><comments>https://news.ycombinator.com/item?id=5592643</comments><guid isPermaLink="false">https://news.ycombinator.com/item?id=5592643</guid></item></channel></rss>