Hello everyone, I spent my weekend optimising the first problem and learned allot in the process about Elixir. I got to 80 points, but still the third hidden test is timing out. Can anyone take a look at the code bellow and give me some pointers on how to improve the performance of the algorithm? …

:waving_hand: Tasks seem unnecessary here. They probably cost more than the value they add over sequentially calling dividedSum/2.

Most Project Euler questions revolve around mathematical insight. This particular question has an O(1) solution! A hint to point you in the right direction is to consider “triangle numbers”, or the 3rd line of Pascal’s triangle. The sum of all the numbers between 0 and 100 can be thought of as (0 +…

Hello, @AlchemistCamp , This is exactly what I am using here, its a bit hidden by the optimizations I tried to make. If you read carefully, I do: 3*(1+2+…+n/3)+5*(1+2+…+n/5)-15*(1+2+…+n/15), where 1+2+…+n/3 and the other series are calculated using the formula Sn = n*(n+1)/2. @idi527 , Indeed, you w…

So I see! I was too quick to write that after seeing the Enum.each in solve. Is the current code still not passing the last test? Edit: My carelessness was the root cause, but maybe renaming dividedSum to something like sum_of_multiples(n, multiple) would make it clearer, also.

The current code, now passes all tests :smiley:

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SMFloris May 12, 2019, 6:40pm 6

The current code, now passes all tests