October Challenge 2019 Division 2
Missing Number, Chef and Maximum Star Value, Array Modification, Operations on a Matrix, Phone Prices, Even Edges
November Challenge 2019 Division 2
Physical Exercise, Hard Sequence, Smallest Beautiful Number, From Zero to Infinity, Single Point of Failure, Weapon Value, Chef and Minimum Colouring
December Challenge 2019 Division 1
Chefina and Ranges, Addition, Binary XOR
January Challenge 2020 Division 1
Chef and Dynamo, Doraemon, Chefina and Prefix Suffix Sums, English
March Challenge 2020 Division 1
Chef and DAG, Winning Ways 2, Lasers Everywhere, Lasers Everywhere Alternative
April Challenge 2020 Division 1
Strange Number, Leaked Answers (Challenge), Factor Tree, Perfect Power Divisors, Squared Subsequences, Ready Bitwise
February Lunchtime 2020 Division 1
Painter Problem, Swapping to Palindrome, Monsters Battle, Secret Mission
March Challenge 2021 Division 1
Space Arrays, Maximum Topological Sort, Random Walk Queries, Locked Safe, Paparazzi Gennady, Consecutive Adding, Dense Graph
April Challenge 2021 Division 1
Binary String MEX, Tree Permutations, Worthy Matrix, Destroy the EMP Chip, Chef and Pair Flips, Chef and Dice, Boolean Game
China