September Challenge 2019 Division 2
Easy Fibonacci, Chef and Good Subsequences, Chef and Interesting Subsequences
October Challenge 2019 Division 2
Array Modification, Operations on a Matrix, Phone Prices
November Challenge 2019 Division 2
Physical Exercise, Hard Sequence, Smallest Beautiful Number, Weapon Value, Chef and Minimum Colouring
December Challenge 2019 Division 2
Plus Multiply, Addition, That Is My Score!, Easy Subsequence Selection, Binary XOR
January Challenge 2020 Division 1
Chef and Dynamo, Doraemon
February Challenge 2020 Division 2
Long Contest and Cook Off Overlaps, (Challenge) Raisins, School of Geometry, The Theatre Problem, No Change Required, Hard Cash
March Challenge 2020 Division 1
Chef and DAG, Lasers Everywhere, Lasers Everywhere Alternative
June Challenge 2020 Division 1
The Tom and Jerry Game!, Covid Sampling (Challenge)
August Challenge 2020 Division 1
Smallest KMP, Chef and Wedding Arrangements, Subsequence Frequency Counting
September Challenge 2020 Division 1
Chefina and Swap, Chef and Trump Cards, Find XOR, Divide Candies, Ada Matrix
October Challenge 2020 Division 1
Positive AND, Replace for X, D-Dimensional MST
Russia