December Challenge 2018 Division 1
Colorblind Feast, (Challenge) Delete DAG, Chef and Interactive XOR, Edge Addition, Max and Electrical Panel, Directing Edges
November Challenge 2018 Division 2
Chef and Happiness, Chef and Difficult Contests, Binary Strings, Magician versus Chef 2, Chef, Primes and Trees (Challenge), Good Median, Appy Loves One, Chef and Ridges
October Challenge 2018 Division 2
Appy and Balloons , Beautiful Bricks, Minimize Digitsum, Chef and Surprise Chessboard, Chef and Serves, Byte to Bit, Chef and Circles
November Lunchtime 2018 Division 1
Beats and Pieces, Median, Useful Number
January Challenge 2019 Division 1
Yet Another Problem About Sequences, Different Neighbours, Partition the Graph, Distinct Pairs, Maximum Distance, Party, (Challenge) Chef and Matching Game, A Pizza Slice
January Lunchtime 2019 Division 1
Wanderer, Mouse Meets Cheese, Rooks, Distances
March Challenge 2019 Division 1
Chef and Soccer, Cheating on Queue, Sonya and Tree, Perfect Tree Problem, Treasure Hunt, Yet Again a Subarray Problem, Matchable Permutations, (Challenge) Interleaving Strings
China