September Challenge 2016
Faded Palindromes, Chef and digits of a number, Chef and calculation
December Challenge 2017
Chef and Universe, Total Diamonds, Chef And his Cake, Chef, Leonardo And Queries, Chef And Easy Xor Queries, Penalty Shoot-out, Red and blue points, Chef and Hamming Distance of arrays
January Challenge 2018
Killing Monsters, K-Concatenation, Maximum Score, Rectangle, String Merging, Partition the numbers
January Cook-Off 2018
Survive in ChocoLand, Multiple of 3, Make array great again
January Lunchtime 2018
Chef and Game with Sequence, Chef and Average on a Tree, Chef and Function, Chef and Escaping from the Labyrinth
February Challenge 2018
Chef and odd queries, Permutation and Palindrome, (Challenge) Biased Committee, Car-pal Tunnel, Points Inside A Polygon, Akanksha and End of Semester, Chef And The Patents, Chef And His Characters, Broken Clock
April Lunchtime 2018 Division 1
The hardest gcd problem, Triple-tree decomposition, Fast forward travelling
April Challenge 2018 Division 1
Cutting Plants, Highway Crossing, Count Good Prefixes
Belarus