| defmodule Bob.Hasher do |
| @moduledoc """ |
| Bob's implementation of the integer hashing challenge. |
| Uses iterative approaches for better performance. |
| """ |
|
|
| @doc """ |
| Computes SHA-256 hash of a string. |
| """ |
| def sha256(input) do |
| :crypto.hash(:sha256, input) |> Base.encode16(case: :lower) |
| end |
|
|
| @doc """ |
| Sums a list of integers iteratively. |
| """ |
| def sum_list(list) do |
| do_sum(list, 0) |
| end |
|
|
| defp do_sum([], acc), do: acc |
| defp do_sum([head | tail], acc), do: do_sum(tail, acc + head) |
|
|
| @doc """ |
| Computes factorial iteratively. |
| """ |
| def factorial(n) do |
| do_factorial(n, 1) |
| end |
|
|
| defp do_factorial(0, acc), do: acc |
| defp do_factorial(n, acc), do: do_factorial(n - 1, acc * n) |
|
|
| @doc """ |
| Main entry point that routes to the appropriate function. |
| """ |
| def solve(:sha256_forge, input), do: sha256(input) |
| def solve(:sum_list, input), do: sum_list(input) |
| def solve(:factorial_5, input), do: factorial(input) |
| def solve(_challenge, _input), do: nil |
| end |
|
|
