March Challenge 2017
Bear and Extra Number, Xenny and Alternating Tasks
April Challenge 2017
Dish Of Life, Bear and Row 01, Similar Dishes
May Challenge 2017
Chef and his daily routine, Courses in an university, Median of adjacent maximum numbers
June Challenge 2017
A Good Set, Chef and the Feast, Xenny and Coin Rankings, Triplets, Pairwise union of sets
October Challenge 2017
Max Mex, Counter Test For CHEFSUM, A Balanced Contest
April Cook-Off 2017
Bear and Candies 123, Bear and AB
March Challenge 2018 DIV 2
Chef and Easy Problem, A Big Sale, Mix the Colors, Chef and Glove, Minions and Voting, Minion Chef and Bananas
December Challenge 2018 Division 2
Chef and An Ideal Problem, Max and Electrical Panel, Chef and Interactive Contests, Chef and Meatballs, Directing Edges, (Challenge) Delete DAG, Chef and Interactive XOR
October Challenge 2018 Division 1
Appy and Balloons , Beautiful Bricks, Minimize Digitsum, Chef and Surprise Chessboard
April Challenge 2019 Division 2
Kira Loves Palindromes, Playing with Numbers, Friend or Girlfriend, Maximum Remaining, Subtree Removal, Fencing
August Challenge 2019 Division 1
Guddu and his Mother, Maximize an Expression, Dilemma, Encoding
September Challenge 2019 Division 1
Biladerim Icin, Fuzzy Linear Combinations, Expected GCD, Chef Designed a Network
February Challenge 2020 Division 1
Chef and Railway Stations, Expected Change, No Change Required, Chef and Gordon Ramsay 2, (Challenge) Raisins, Long Contest and Cook Off Overlaps
Vietnam