indexを1ずつ変えるだけで辿れる非常に面白い二分木です This is a very interesting binary tree that can be traversed simply by changing the index by 1 each time.
普通のよりリストも参照しないし無駄な演算もないし軽いかも？ It might be lighter than the usual method because it doesn't reference lists and doesn't use unnecessary calculations?
