説明
『I Know an Old Lady Who Swallowed a Fly』という歌の歌詞を生成しましょう。
歌詞をそのままコピー＆ペーストしたり、ファイルから読み込んだりしてもかまいませんが、アルゴリズム的に解いてみると、この問題はずっと面白くなります。
これは、作者不明の累積歌です。
よく知られている数あるバリエーションのうちのひとつです。
I know an old lady who swallowed a fly.
I don't know why she swallowed the fly. Perhaps she'll die.
I know an old lady who swallowed a spider.
It wriggled and jiggled and tickled inside her.
She swallowed the spider to catch the fly.
I don't know why she swallowed the fly. Perhaps she'll die.
I know an old lady who swallowed a bird.
How absurd to swallow a bird!
She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.
She swallowed the spider to catch the fly.
I don't know why she swallowed the fly. Perhaps she'll die.
I know an old lady who swallowed a cat.
Imagine that, to swallow a cat!
She swallowed the cat to catch the bird.
She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.
She swallowed the spider to catch the fly.
I don't know why she swallowed the fly. Perhaps she'll die.
I know an old lady who swallowed a dog.
What a hog, to swallow a dog!
She swallowed the dog to catch the cat.
She swallowed the cat to catch the bird.
She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.
She swallowed the spider to catch the fly.
I don't know why she swallowed the fly. Perhaps she'll die.
I know an old lady who swallowed a goat.
Just opened her throat and swallowed a goat!
She swallowed the goat to catch the dog.
She swallowed the dog to catch the cat.
She swallowed the cat to catch the bird.
She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.
She swallowed the spider to catch the fly.
I don't know why she swallowed the fly. Perhaps she'll die.
I know an old lady who swallowed a cow.
I don't know how she swallowed a cow!
She swallowed the cow to catch the goat.
She swallowed the goat to catch the dog.
She swallowed the dog to catch the cat.
She swallowed the cat to catch the bird.
She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.
She swallowed the spider to catch the fly.
I don't know why she swallowed the fly. Perhaps she'll die.
I know an old lady who swallowed a horse.
She's dead, of course!
ヒント
この演習はコードのリファクタリングがテーマなので、テストにすでに合格している解答を用意しています。
この解答を、自分が誇れるまで書き直し、その過程で何かを学ぶことが挑戦です。
どこから始めればいいかわからない場合は、こんなアイデアがあります。
- 繰り返しをできるだけ少なくしてみましょう。
- コードを読みやすくしてみましょう。
- 解答を一般化して、おばあさんがほかのものも飲み込めるようにしてみましょう。
焦らず、ゆっくり進めましょう。
一度に1つずつ変更して、解答がまだテストに合格するか確認してください。
楽しんでください！
