September Challenge 2017
Minimum Good Permutation, Little Chef and Sums, Chef and Pick Digit
October Challenge 2017
Max Mex, A Balanced Contest
November Challenge 2017
Chef Hates Palindromes, Chef goes Left Right Left, Periodic Palindrome Construction, Villages and Tribes
December Challenge 2017
Total Diamonds, Chef And his Cake, Penalty Shoot-out, Chef and Hamming Distance of arrays
January Challenge 2018
K-Concatenation, Maximum Score, Rectangle, Partition the numbers
February Challenge 2018
Chef And His Characters, Chef And The Patents, Car-pal Tunnel, Permutation and Palindrome
March Challenge 2018 DIV 2
Minion Chef and Bananas, Minions and Voting, Chef and Glove, A Big Sale, Chef and Easy Problem, Mix the Colors
April Challenge 2018 Division 2
Weight of Numbers, Highway Crossing, Count Good Prefixes, Average of Pairs, Workers
August Challenge 2018 Division 2
Modular GCD, Problem Sort, Sheokand and Number, Spell Bob
December Challenge 2018 Division 1
Max and Electrical Panel, Chef and Interactive XOR, Directing Edges, (Challenge) Delete DAG
November Challenge 2018 Division 2
Chef and Ridges, Appy Loves One, Good Median, Chef, Primes and Trees (Challenge), Magician versus Chef 2, Chef and Difficult Contests, Chef and Happiness
Encoder (Rated for Division 2)
Knight Chess, Paint the Wall
April Challenge 2019 Division 1
Kira Loves Palindromes, Playing with Numbers, Subtree Removal
Azerbaijan