November Challenge 2017
Chef and Subarray Queries, Chef Hates Palindromes, Villages and Tribes, Periodic Palindrome Construction, Chef goes Left Right Left
January Challenge 2018
Killing Monsters, K-Concatenation, Maximum Score, Rectangle, String Merging, Partition the numbers
February Challenge 2018
Chef And His Characters, Chef And The Patents, Permutation and Palindrome
March Challenge 2018 DIV 1
Minions and Voting, Mix the Colors, Chef and Gcd Queries, Pishty and Triangles, Chef and Easy Problem
May Cook-off 2018 Division 1
Difficult Choice, Best Cake Ever
July Cook-Off 2018 Division 1
Sticks, OR Matrix, Chef and GCD Game
July Challenge 2018 Division 1
No Minimum No Maximum, Gears, Reach Equilibrium, Pizza Delivery
June Lunchtime 2018 Division 1
Sort the Leaves, Permutation Composition Queries, Summary Power
July Lunchtime 2018 Division 1
Forced Particles, GCD Sum, Make a String, Prime divisors
Iran