February Challenge 2018
Chef And Land Labeling, Chef And His Characters, Chef And The Patents, Chef and odd queries, Points Inside A Polygon, Car-pal Tunnel, (Challenge) Biased Committee, Permutation and Palindrome, Broken Clock
May Challenge 2018 Division 2
Minimum Deletions, Dibs on Fibs, Fake Binary Search, Not a Convex Hull (Challenge), Xor Again, Change the Signs, Mighty Friend, S-T Mincut
June Challenge 2018 Division 1
Two Flowers, Vision, Ways to Work, Expected Buildings, Archi and Tree
April Challenge 2019 Division 1
Kira Loves Palindromes, Moving Rectangles (Challenge), Subtree Removal, Mininum XOR over Tree, Offer for Chef, Playing with Numbers
May Challenge 2019 Division 1
Ada Rooks 2, Where to Build the Roads
June Challenge 2019 Division 1
(Challenge) SnackDown 99, Sum and GCD, Intersecting Paths, Chef and His Dish, Chef and Ingredients, Lent Money
August Challenge 2021 Division 1 (Unrated)
Special Triplets, Array Filling, Geometry 1, Chef and Bulb Invention, Alternating LG Queries, Charge Scheduling, Chef and Digits of Large Numbers, Fat Hut, Problem Difficulties, Olympics Ranking
Vietnam