29 lines
1.4 KiB
Markdown
29 lines
1.4 KiB
Markdown
# Hints
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## General
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- Use the built-in [(linked) list type][list].
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- Use the built-in [`Stream`][stream] module functions to create a stream
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## 1. Generate the base cases
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- You can use multiple [function clauses][multiple-fn-clauses] and [pattern-matching][pattern-matching] to create the base case functions.
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## 2. Create the generalized case
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- Use the [`Stream.iterate/2`][stream-iterate] function to generate a sequence of numbers, with the next being created from the previous.
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- The starting numbers are `2` then `1`, which you can pass in together using a tuple to make a pair `{2, 1}`
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- Make sure the next number is the sum of the two numbers previous to it.
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- To evaluate the stream to a list, use an [`Enum`][enum] function.
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## 3. Catch bad arguments
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- Use a [guard][guards] to catch the cases when an integer isn't passed as an argument to `generate/1`.
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[enum]: https://hexdocs.pm/elixir/Enum.html#content
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[guards]: https://hexdocs.pm/elixir/master/patterns-and-guards.html#guards
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[list]: https://elixir-lang.org/getting-started/basic-types.html#linked-lists
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[multiple-fn-clauses]: https://elixir-lang.org/getting-started/modules-and-functions.html#named-functions
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[pattern-matching]: https://elixir-lang.org/getting-started/pattern-matching.html#pattern-matching-1
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[stream]: https://hexdocs.pm/elixir/Stream.html#content
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[stream-iterate]: https://hexdocs.pm/elixir/Stream.html#iterate/2 |