July Challenge 2018 Division 2
Chef and War with Taran (Challenge), Reach Equilibrium, No Strings Attached, Strike or Spare, Magic Set, Gears, No Minimum No Maximum, Subway Ride
August Challenge 2018 Division 2
Coordinate Compression , Modular GCD, Problem Sort, Princess and Dragons, Lonely Cycles, Sheokand and Number, Spell Bob
October Challenge 2018 Division 1
Distinct Rows in Submatrices, Coprime Components, (Challenge) Chef and Takonemo, Chef and Surprise Chessboard, Beautiful Bricks, Appy and Balloons , Walk on Tree, Minimize Digitsum
April Challenge 2019 Division 1
Edgy, Sonya and Queries, Moving Rectangles (Challenge), Subtree Removal, Playing with Numbers, Mininum XOR over Tree, Kira Loves Palindromes, Offer for Chef
May Challenge 2019 Division 1
(Challenge) Chef Exchange, Ada Rooks 2, Trees and Degrees, Chef and Elephant Tree, Where to Build the Roads, Sonya and Gifts, Ada Pawns
China