June Challenge 2017
Chef and Prime Queries, A Good Set, Cloning, Chef and the Feast, Xenny and Coin Rankings, Triplets, Pairwise union of sets, Persistent oak
June Lunchtime 2017
Maximum Unique Segment, Two Numbers, Company and Club Hierarchies
January Challenge 2018
Maximum Score, Partition the numbers, String Merging, Rectangle, K-Concatenation, Killjee and k-th letter , A humongous Query, Killing Monsters
February Challenge 2018
Broken Clock, 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
October Challenge 2018 Division 1
Appy and Balloons , Distinct Rows in Submatrices, Coprime Components, Minimize Digitsum, Beautiful Bricks, Chef and Surprise Chessboard
October Lunchtime 2018 Division 1
Robots Again, Coloring the Grid, Weird Question, Niceness of the Arrays
Encoder (Rated for Division 2)
Knight Chess, Country Tour, Second Largest Element, Old Farmer, Paint the Wall
January Challenge 2019 Division 1
Different Neighbours, A Pizza Slice, (Challenge) Chef and Matching Game, Party, Maximum Distance, Distinct Pairs, Partition the Graph, Yet Another Problem About Sequences
March Challenge 2019 Division 1
Chef and Soccer, Cheating on Queue, Perfect Tree Problem, Yet Again a Subarray Problem, Matchable Permutations, (Challenge) Interleaving Strings
Taiwan