Project Euler (in Scala)

This project contains a short selection of problems from Project Euler (https://projecteuler.net/) to be solved in Scala.

It was build in the context of a hacking session for beginners at the BeScala (Belgian Scala User Group).

The selected problem numbers are: 1, 3, 5, 6, 7, 9, 10, 13, 15, 18, 21, 24 and 25

##Instructions

start sbt

run command 'euler *ProblemXXX' or 'euler-all' (where XXX is to be replaced by the problem number)

To start, you can run: sbt "euler *Problem001"
(NOTE: problem numbers are left-padded with 0 up to 3 digits)

The problem/test will run in continuous mode.

You can open the file Problem001.scala and add your solution.

class Problem001 extends EulerSuite {
  euler(problem(1)) {
    TODO // add your solution here - MUST return a Long!!!
  }
}

Alternative implementations

You can add alternative implementations for each problem. To do that you need to pass a alternative name for the problem.

class Problem001 extends EulerSuite {
  euler(problem(1)) {
    TODO // your first solution goes here
  }
  euler(problem(1), "alternative solution") {
    TODO // your alternative solution goes here
  }
}

Elapsed time

Time elapsed to run each solution is displayed in nanoseconds and milliseconds. Therefore you can compare the efficiency of different solutions.

Problem000.scala contains a demo problem with a solution. You can use it as implementation example.

Bellow we see the output of Problem000.

[info] Problem000:
[info] - Problem #0
[info]   +
[info]   + Description:
[info]   +   Find the sum of all numbers from 1 to 100
[info]   +   that are NOT multiples of 7
[info]   + ------------------------------------------------------
[info]   +
[info]   + Elapsed time: 13ms
[info]   + Your solution: 4315
[info]   +
[info] - Problem #0 (alternative impl)
[info]   +
[info]   + Description:
[info]   +   Find the sum of all numbers from 1 to 100
[info]   +   that are NOT multiples of 7
[info]   + ------------------------------------------------------
[info]   +
[info]   + Elapsed time: 8ms
[info]   + Your solution: 4315
[info]   +

###Getting started

When you start working on the given problems, you will soon find out that you need to solve a number of generic problems over and over again. In order to give you a head start, a package object is included in the org.bescala.projecteuler package that contains a number of useful functions such as a prime number generator, decomposition of a number in prime factors, etc.

We're not forcing you to use these functions: if you don't want to use them, just ignore them and roll your own. If you do, look at the source code, or alternatively, look at the Scaladoc we've generated (doc/index.html).

Note that when you browse the main page, you will only see the object Integers. you can get to the other functions by clicking on package org.bescala.projecteuler in the left navigation pane.