Codeforces Round #318 [RussianCodeCup Thanks-Round] (Div. 2) B. Bear and Three Musketeers
Codeforces Round #319 (Div. 1) A. Vasya and Petya’s Game
Codeforces Round #321 (Div. 2) B. Kefa and Company
Atoi
Zigzag String
Multiply Strings
Roman To Integer
Integer To Roman
D - Not Divisible
D - Sum of Divisors