Time for the file-based merge sort code promised long ago. BSD licensed. Yes, I know it’s way too verbose, quite inefficient and probably pretty ugly but hey it’s just a general idea for you to improve and adjust to your specific needs. It’s intentionally this clear It can sort things you wouldn’t be able to
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I’m alive and well. In case you wondered what was stopping me from posting recently, the answer is PE #289, PE #294 and now the most recent PE #304. The last one was really easy (I had fallen asleep right before it was posted and got to it the next day, still made it to
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For a positive integer n, define f(n) as the least positive multiple of n that, written in base 10, uses only digits <=2. Thus f(2)=2, f(3)=12, f(7)=21, f(42)=210, f(89)=1121222. Also sum_n=1^100 {f(n)/n} = 11363107 Find sum_n=1^10000 {f(n)/n}. Phew… this was an easy one I made it to the top 30. I hope I will be
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During my struggles with Project Euler Problem #302 I made an attempt to semi-brute force it. Unfortunately it required huge amounts of RAM (about 2e9 * 16 bytes) so I figured I could use some help from permanent storage. I implemented two helper classes, namely MergeSort and SwapIterator which look like this: In both cases
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In a very simplified form, we can consider proteins as strings consisting of hydrophobic (H) and polar (P) elements, e.g. HHPPHHHPHHPH. For this problem, the orientation of a protein is important; e.g. HPP is considered distinct from PPH. Thus, there are 2n distinct proteins consisting of n elements. When one encounters these strings in nature,
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I haven’t been posting for the past few days because I’ve been in Wrocław (Breslau) for the weekend and then I was kinda busy playing with new coding quests, this time from topcoder.com, my second big love after Project Euler (jeez, why nobody told me about these two before? ). I’ve noticed that usually three
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Jeez, now I’ve solved Project Euler problems #297 and #299. I think I’m becoming an addict #299 required quite a lot of help from my friend (thank you ) while #297 was particularly easy. I managed to code it correctly in about 15 minutes Can you? ;D Each new term in the Fibonacci sequence is
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Omg, I finally solved this problem and gained access to Project Euler’s thread dedicated to its solutions. Apparently everybody came up with basically the same idea. The number of game states can be reduced to 438 (439 including the empty state). This way all 50 rounds can be simulated using dynamic programming. I’m not sure
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I’ve recently discovered Project Euler site – www.projecteuler.net and found one of its most recent puzzles quite a fun to solve I mean project #298 – Selective Amnesia. It’s a cache hit/miss problem although formulated using different terms. Larry and Robin play a memory game involving a sequence of random numbers between 1 and 10,
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