Day 15: Linked List
https://www.hackerrank.com/challenges/30-linked-list/problem
Recent posts
日本のウイスキー 人気が高すぎて足りなくなる
https://www3.nhk.or.jp/news/easy/k10011726451000/k10011726451000.html
Day 9: Recursion 3
https://www.hackerrank.com/challenges/30-recursion/problem
Day 8: Dictionaries and Maps
https://www.hackerrank.com/challenges/30-dictionaries-and-maps/problem
Day 7: Arrays
https://www.hackerrank.com/challenges/30-arrays/problem