May Challenge 2017
Chef and his daily routine, Courses in an university, Blocked websites, Median of adjacent maximum numbers, Chef and Subsequences, Chef and Sub Array
June Challenge 2017
Chef and Prime Queries, A Good Set, Chef and the Feast, Xenny and Coin Rankings, Triplets, Pairwise union of sets
July Challenge 2017
Whats in the Name, IPC Trainers, Calculator , Tree Expectancy, Pishty and tree, Chef and Sign Sequences
October Challenge 2017
Max Mex, A Balanced Contest
October Cook-Off 2017
Chef and Counting Test, Chef and Employment Test, Chef and Weird Queries
March Challenge 2019 Division 1
Cheating on Queue, Yet Again a Subarray Problem
April Challenge 2019 Division 1
Playing with Numbers, Subtree Removal
Russia