March Challenge 2017
Completing favorite game, Cooking Schedule, Bandwidth of a matrix, (CH) Bear and Sorted Rows, Bear and Cat Trap, Bear and Extra Number, Xenny and Alternating Tasks, Path Triples On Tree, Sum of distances, Pishty and birthday
June Challenge 2017
Cloning, Pairwise union of sets, Triplets, Xenny and Coin Rankings, Chef and the Feast, A Good Set, Euler Sum, Saboteur (Challenge), Chef and Prime Queries, Persistent oak
November Challenge 2017
Villages and Tribes, Periodic Palindrome Construction, Lovers Gift, Chef goes Left Right Left, Polynomials, Chef Hates Palindromes, Day Schedule, Product on the segment by modulo , Chef and Intersection Line, Chef and Subarray Queries
October Cook-Off 2017
Chef and Counting Test, Chef and Employment Test, Chef and Weird Queries, Chef and Dancing Steps
October Lunchtime 2017
Maximum Number, Buggy Calculator, Optimal Subset, Weird Competition
January Challenge 2018
A humongous Query, K-Concatenation, Maximum Score, Rectangle, String Merging, Partition the numbers
May Lunchtime 2018 Division 1
Sum on Tree, Count Substrings, Shifted Palindrome, Weak in the Middle, Maximum Plus
Canada