Exercises

Modules and Functions - Sum

Write functions sum(n) that uses recursion to calculate the sum of integers from 1 to n.

defmodule Recursive do
  def sum(_n) do
    # Your code here
  end
end

1 = Recursive.sum(1)
6 = Recursive.sum(3)
10 = Recursive.sum(4)

FizzBuzz

Write a function that returns the numbers from 1 to n. But for multiples of:

• three replaces a number with an atom :fizz instead of the number
• five replaces a number with an atom :buzz
• both three and five replaces a number with an atom :fizzbuzz.

Tip: see How to use div/2 and/or rem/2?

defmodule FizzBuzz do
  def fizzbuzz(_n) do
    # Your code here
  end
end

[] = FizzBuzz.fizzbuzz(0)
[1] = FizzBuzz.fizzbuzz(1)
[1, 2] = FizzBuzz.fizzbuzz(2)
[1, 2, :fizz] = FizzBuzz.fizzbuzz(3)

[
  1,
  2,
  :fizz,
  4,
  :buzz,
  :fizz,
  7,
  8,
  :fizz,
  :buzz,
  11,
  :fizz,
  13,
  14,
  :fizzbuzz,
  16,
  17,
  :fizz,
  19,
  :buzz,
  :fizz,
  22,
  23,
  :fizz,
  :buzz,
  26,
  :fizz,
  28,
  29,
  :fizzbuzz,
  31
] = FizzBuzz.fizzbuzz(31)

Scrabble Score

Given a word, compute the Scrabble score of that word.

Letter Values

Tip: You may find String.graphemes/1 useful.

defmodule Scrabble do
  def calculate_score(_word) do
    # Your code here
  end
end

13 = Scrabble.calculate_score("elixir")
2 = Scrabble.calculate_score("is")
6 = Scrabble.calculate_score("fun")