用 Elixir 计算 anagram

Anagram（易位构词）是把某个单词或词组的字母重新排列后得到的另一个单词或词组，通常每个原始字母都恰好用一次

例如：

• "restful" = "fluster"
• "funeral" = "real fun"
• "adultery" = "true lady"
• "customers" = "store scum"
• "forty five" = "over fifty"

用 mix new anagram 创建一个新项目，然后我们来写几个测试用例：

defmodule AnagramTest do
  use ExUnit.Case

  test "calculates anagram" do
    assert Anagram.anagram?("restful", "fluster") == true
    assert Anagram.anagram?("funeral", "realfun") == true
    assert Anagram.anagram?("adultery", "truelady") == true
    assert Anagram.anagram?("customers", "storescum") == true
    assert Anagram.anagram?("fortyfive", "overfifty") == true
    assert Anagram.anagram?("fiftyfive", "overfifty") == false
    assert Anagram.anagram?("funeral", "real fun") == false
  end
end

接下来我们要写代码：

defmodule Anagram do
    def anagram?(a, b) do
    charlist(a) == charlist(b)
  end

  def charlist(w) do
    w |> String.trim() |> String.downcase() |> String.graphemes() |> Enum.sort()
  end
end

运行测试 mix test：

Compiling 1 file (.ex)
Generated anagram app
.

Finished in 0.1 seconds
1 test, 0 failures

Randomized with seed 752850

完成，现在你有一个 anagram 计算器了！