December Challenge 2018 Division 2
(Challenge) Delete DAG, Max and Electrical Panel, Chef and Interactive XOR, Chef and Interactive Contests, Chef and An Ideal Problem
January Challenge 2019 Division 2
Lucky Number Game, Distinct Pairs, Fancy Quotes
February Challenge 2019 Division 2
Chef and Magical Jars, Deputy Chef, Art of Balance, Appy and Contest, Chef and Secret Ingredients
March Challenge 2019 Division 2
Chef and Number Game, Chef and a Beautiful Digit
December Challenge 2019 Division 2
Chefina and Ranges, Addition, That Is My Score!, Sticky Notes, Easy Subsequence Selection, Binary XOR, Plus Multiply
December Lunchtime 2019 Division 2
The Evil Professor, Stupid Machine, Check Algorithm
January Challenge 2020 Division 1
Chef and Dynamo, Doraemon, Chefina and Prefix Suffix Sums
May Challenge 2020 Division 1
Buying a New String, Triple Sort, Chef and Bitwise Product
Bangladesh