May Challenge 2017
Courses in an university, Chef and his daily routine, Median of adjacent maximum numbers
June Challenge 2017
A Good Set, Xenny and Coin Rankings
August Long Challenge 2017
Chef and Rainbow Array, Chef and Mover, Palindromic Game, Greedy Candidates
September Challenge 2017
Sereja and Commands, Chef and Pick Digit, Minimum Good Permutation, Little Chef and Sums
October Challenge 2017
A Balanced Contest, Max Mex
December Challenge 2017
Total Diamonds, Chef And his Cake, Chef And Easy Xor Queries, Penalty Shoot-out, Chef and Hamming Distance of arrays
January Challenge 2018
K-Concatenation, Maximum Score, Rectangle, String Merging
September Mega Cook-Off 2018 Division 2
Make a Permutation, ATM Machine
March Lunchtime 2019 Division 2
Testing Robot, Pogo Stick Competition
April Challenge 2019 Division 1
Maximum Remaining, Subtree Removal
December Challenge 2019 Division 2
Chefina and Ranges, Plus Multiply, Binary XOR, Easy Subsequence Selection, Sticky Notes, (Challenge) Cubical Virus, That Is My Score!, Addition
July Challenge 2020 Division 1
LCM Constraints, Doctor Chef, Missing a Point, Chef and Dragon Dens, Chefina and Swaps
September Challenge 2020 Division 1
Chefina and Swap, Chef and Trump Cards, Find XOR, Ada Matrix
March Lunchtime 2022 Division 1
Winter, Adjacency Love, Separate Them All
India