October Challenge 2019 Division 2
Even Edges, Queries on Matrix, Phone Prices, Operations on a Matrix, (Challenge) Maximizing LIS, Array Modification, Chef and Maximum Star Value, Bacterial Reproduction, Missing Number, Fun with Lists
November Challenge 2019 Division 2
Chef and Minimum Colouring, (Challenge) Coloring Triangulations, Weapon Value, Winning Ways, Single Point of Failure, A Simple Game, From Zero to Infinity, Smallest Beautiful Number, Hard Sequence, Physical Exercise
December Challenge 2019 Division 1
Chefina and Ranges, Binary XOR, Binomial Fever, Scoring Pairs, Sticky Notes, Test Generation, (Challenge) Cubical Virus, Addition
January Challenge 2020 Division 1
Army of Me, English, Chefina and Prefix Suffix Sums, Doraemon, Chef and Dynamo, Doofish Matrix
February Challenge 2020 Division 1
Chef and Railway Stations, Expected Change, No Change Required, Chef and Gordon Ramsay 2, Long Contest and Cook Off Overlaps
March Challenge 2020 Division 1
Egg-free DAG, Good Subsequences, (Challenge) 300 IQ Ants, Lasers Everywhere Alternative, Lasers Everywhere, Winning Ways 2, Break, Chef and DAG, Inverse of a Function
April Challenge 2020 Division 1
Strange Number, Squared Subsequences, Perfect Power Divisors, Ready Bitwise, Factor Tree
May Challenge 2020 Division 1
Precise Bipartite Pairing, Precise Pairing, (Challenge) Nanobots, Chef and Bitwise Product, Chef and Rainbow Road, Not a Real World Problem, Sorting Vases, Binary Land, Triple Sort, Buying a New String
China