December Challenge 2018 Division 1
Max and Electrical Panel, Directing Edges, Chef and Interactive XOR, (Challenge) Delete DAG
November Challenge 2018 Division 2
Chef and Ridges, Appy Loves One, Good Median, Chef, Primes and Trees (Challenge), Magician versus Chef 2, Chef and Difficult Contests, Chef and Happiness
October Challenge 2018 Division 2
Minimize Digitsum, Chef and Circles, Byte to Bit, Chef and Serves, Appy and Balloons
January Challenge 2019 Division 1
Yet Another Problem About Sequences, Different Neighbours, Distinct Pairs
October Challenge 2019 Division 1
Chef and Maximum Star Value, Array Modification
March Challenge 2020 Division 2
XOR Engine, Lasers Everywhere, Pintu and Fruits
Thailand