May Challenge 2017
Courses in an university, Chef and his daily routine, Median of adjacent maximum numbers
June Challenge 2017
A Good Set, Chef and the Feast, Xenny and Coin Rankings, Triplets, Pairwise union of sets
July Challenge 2017
Chef and Sign Sequences, Whats in the Name
August Long Challenge 2017
Chef and Mover, Palindromic Game, Chef and Rainbow Array
October Challenge 2017
Chef and a great voluntary Program, Max Mex, Counter Test For CHEFSUM, A Balanced Contest
July Cook-Off 2017
Chang and Bitwise OR, Chang and the Perfect Function
September Lunchtime 2017
Chef and Dice, Chef and Cook-Off Contests
January Challenge 2018
K-Concatenation, Maximum Score, Rectangle, String Merging
March Challenge 2018 DIV 2
A Big Sale, Minion Chef and Bananas, Minions and Voting, Chef and Glove, Mix the Colors, Chef and Easy Problem, Pishty and Triangles
September Mega Cook-Off 2018 Division 2
OneTwo, ATM Machine, Make a Permutation
April Challenge 2018 Division 1
Cutting Plants, Count Good Prefixes
India