December Challenge 2015
Plane Division, Chef and the stones
September Challenge 2016
Faded Palindromes, Chef and calculation, Chef and digits of a number
October Challenge 2016
Chef and Keyboard, Fenwick Iterations, Chef and Three Dogs
June Challenge 2017
Xenny and Coin Rankings, Pairwise union of sets, Triplets, Chef and the Feast, A Good Set, Chef and Prime Queries
July Challenge 2017
Chef and Sign Sequences, Whats in the Name, Calculator , IPC Trainers
August Long Challenge 2017
Greedy Candidates, Palindromic Game, Chef and Rainbow Array, Chef and Mover
November Challenge 2017
Chef Hates Palindromes, Chef goes Left Right Left, Periodic Palindrome Construction, Villages and Tribes
September Cook-Off 2017
Infinite OR Game, Statistics Construction, Subsequence Equality
November Challenge 2019 Division 2
Hard Sequence, Chef and Minimum Colouring, Weapon Value, From Zero to Infinity, Physical Exercise
March Challenge 2021 Division 2
Interesting XOR!, College Life 4, Space Arrays
March Long Two 2022, Division 2 (Unrated)
Missing Numbers, Same Parity Swaps in Binary Strings
Vietnam