Overview
Usually I try to solve the original challenge from Project Euler first and then tackle its modified version at Hackerrank which is often harder.
I'm a software developer and don't have the mathematical knowledge to solve most of the hard problems.
However, I'm quite good when the solution "just" requires a smart choice of data structures and/or clever use of raw CPU power.
If you look at my overview then you'll see that I never solved a problem with a rating of more than 70%.
And with about 300 solved problems I'm hitting a wall: no easy problems are left and most of the unsolved problems just don't interest me.
My favorite problems are those with a Dynamic Programming solution.
And of course these little gems that can be somehow applied to real-life computer problems:
Some code snippets are part of several problems and I added them to my toolbox.
Heatmap
Please click on a problem's number to open my solution to that problem:
green | solutions solve the original Project Euler problem and have a perfect score of 100% at Hackerrank, too | |
yellow | solutions score less than 100% at Hackerrank (but still solve the original problem easily) | |
gray | problems are already solved but I haven't published my solution yet | |
blue | solutions are relevant for Project Euler only: there wasn't a Hackerrank version of it (at the time I solved it) or it differed too much | |
orange | problems are solved but exceed the time limit of one minute or the memory limit of 256 MByte | |
red | problems are not solved yet but I wrote a simulation to approximate the result or verified at least the given example - usually I sketched a few ideas, too | |
black | problems are solved but access to the solution is blocked for a few days until the next problem is published | |
the flashing problem is the one I solved most recently |
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I scored 13526 points (out of 15700 possible points, top rank was 17 out of ≈60000 in August 2017) at Hackerrank's Project Euler+.
My username at Project Euler is stephanbrumme while it's stbrumme at Hackerrank.
Look at my progress and performance pages to get more details.
Most recently solved
November 15, 2017: Problem 516 - 5-smooth totientsNovember 14, 2017: Problem 290 - Digital Signature
November 12, 2017: Problem 248 - Numbers for which Euler's totient function equals 13!
November 11, 2017: Problem 208 - Numbers for which Euler's totient function equals 13!
November 3, 2017: Problem 386 - Maximum length of an antichain
November 1, 2017: Problem 216 - Investigating the primality of numbers of the form 2n^2-1
October 27, 2017: Problem 327 - Rooms of Doom
October 26, 2017: Problem 358 - Cyclic numbers
October 23, 2017: Problem 587 - Concave triangle
October 19, 2017: Problem 288 - An enormous factorial
... and 289 more ...