June Challenge 2017
Chef and the Feast, A Good Set, Pairwise union of sets, Xenny and Coin Rankings, Triplets
August Long Challenge 2017
Chef and Rainbow Array, Chef and Mover, Palindromic Game, Greedy Candidates
September Challenge 2017
Chef and Pick Digit, Minimum Good Permutation, Little Chef and Sums
October Challenge 2017
Max Mex, A Balanced Contest
April Challenge 2018 Division 2
Chef and Array (Challenge), Weight of Numbers, Highway Crossing, Count Good Prefixes, Average of Pairs, Workers
August Challenge 2018 Division 2
Sheokand and Number, Problem Sort, Modular GCD
Code Melange (Rated)
XD Subsequences, The Deadly Sin, Candy Love
Code Melange (Rated for all)
Greg and Grid, A Small Array, Go Round, Max power
June Challenge 2020 Division 2
Chef and String, Chef and Price Control, Chef and Icecream, The Tom and Jerry Game!, Even Matrix
September Challenge 2020 Division 2
Chefina and Swap, A Problem on Sticks, Chef and Trump Cards, Find XOR, Ada Matrix, Coronavirus Spread 2
August Lunchtime 2020 Division 2
Game on a Strip, Mode of Frequencies, Ratings and Rankings
India