May Challenge 2018 Division 2
Mighty Friend, Change the Signs, Edges in Spanning Trees, Minimum Deletions, Xor Again, Not a Convex Hull (Challenge), Fake Binary Search, Dibs on Fibs, S-T Mincut
November Challenge 2018 Division 2
Chef and Happiness, Chef and Difficult Contests, Binary Strings, Magician versus Chef 2, Good Median, Appy Loves One, Chef and Ridges, Chef, Primes and Trees (Challenge)
January Challenge 2019 Division 1
(Challenge) Chef and Matching Game, A Pizza Slice, Party, Maximum Distance, Distinct Pairs, Partition the Graph, Different Neighbours, Yet Another Problem About Sequences
June Challenge 2019 Division 1
Lent Money, Count Arrays, Chef and Ingredients, Chef and His Dish, Intersecting Paths, Sum and GCD, Forgotten Tree 9, (Challenge) SnackDown 99
China