December Challenge 2014
Chef Under Pressure, Sereja and GCD, Chef and Apple Trees, Alok-nath and His Sanskars, Chef and Bracket-Pairs
January Challenge 2015
Queries on the String, Chef and A Large Permutation, Chef and Stones, Sereja and Votes, One Dimensional Kingdoms, Gcd Queries
June Challenge 2016
Chef and Rectangle Array, Devu and an Array, Chef and cities, Chef and Coins Game, Chef And Binary Operation, Chef and Array and K, Chef And The Hiring Event
July Challenge 2016
Chefland and Electricity, Chef and Robots Competition, Chef and Tetris, Chef and Segments, Andrash and Stipendium, Chef and special numbers
August Challenge 2016
Chef and Circle Run, Chef and Chocolate, Chef and Round Run, Funny gnomes
September Challenge 2016
Chef and digits of a number, Faded Palindromes, Chef and calculation
May Challenge 2017
Gotham PD, Chef and Subsequences
October Challenge 2019 Division 2
Even Edges, Missing Number, Bacterial Reproduction, Chef and Maximum Star Value, Array Modification, Operations on a Matrix, Phone Prices
November Challenge 2019 Division 1
A Simple Game, Single Point of Failure
China