May Challenge 2017
Long Sandwich , Gotham PD, Chef and his daily routine, Courses in an university, Blocked websites, Median of adjacent maximum numbers, Chef and Subsequences, Chef and Sub Array
June Challenge 2017
A Good Set, Pairwise union of sets, Triplets, Xenny and Coin Rankings, Chef and the Feast, Cloning, Chef and Prime Queries
August Long Challenge 2017
Chef And Fibonacci Array, Strings and Graphs, Greedy Candidates, Palindromic Game, Walks on the binary tree, Hill Jumping, Chef and Mover, Chef and Rainbow Array
September Challenge 2017
Sereja and Commands, Chef and Pick Digit, Minimum Good Permutation, Weasel does Xor on Tree, Fill The Matrix, Little Chef and Sums
October Challenge 2017
Chef and a great voluntary Program, Max Mex, Counter Test For CHEFSUM, A Balanced Contest
China