June Challenge 2017
A Good Set, Pairwise union of sets, Chef and the Feast, Xenny and Coin Rankings
July Challenge 2017
Chef and Sign Sequences, Tree Expectancy, Whats in the Name, Calculator , IPC Trainers
August Long Challenge 2017
Chef and Rainbow Array, Greedy Candidates
October Challenge 2017
Chef and Magic Arrays, A Balanced Contest, Counter Test For CHEFSUM, Max Mex, Shooting on the array, Chef and Cycled Cycles, Chef and a great voluntary Program
December Challenge 2017
Chef and Hamming Distance of arrays, Penalty Shoot-out, Chef And Easy Xor Queries, Total Diamonds, Chef And his Cake
June Lunchtime 2017
Maximum Unique Segment, Two Numbers
January Challenge 2018
Rectangle, Partition the numbers, String Merging, Maximum Score, K-Concatenation
March Challenge 2018 DIV 1
Pishty and Triangles, Chef and Easy Problem, Chef and Gcd Queries, Mix the Colors, Minions and Voting
May Cook-off 2018 Division 1
Best Cake Ever, Secret Recipe
India