September Challenge 2017
Minimum Good Permutation, Chef and Pick Digit, Little Chef and Sums
October Challenge 2017
Max Mex, A Balanced Contest
November Challenge 2017
Chef goes Left Right Left, Periodic Palindrome Construction, Villages and Tribes
January Challenge 2018
K-Concatenation, Maximum Score, Rectangle
February Challenge 2018
Car-pal Tunnel, Permutation and Palindrome, Chef And The Patents, Chef And His Characters
March Challenge 2018 DIV 2
A Big Sale, Mix the Colors, Chef and Glove
September Mega Cook-Off 2018 Division 2
ATM Machine, Make a Permutation
October Mega Cook-Off 2018 Division 2
Binary Nim 2, Ada and the Staircase
August Challenge 2018 Division 2
Problem Sort, Sheokand and Number, Spell Bob, Modular GCD
September Challenge 2018 Division 2
Magician versus Chef, War of XORs, Chef and Adventures, Bad Shuffle
October Challenge 2018 Division 2
Minimize Digitsum, Chef and Serves, Byte to Bit
June Lunchtime 2018 Division 2
Summary Power, Counting Pretty Numbers
August Lunchtime 2018 Division 2
Chef and Problem Setting, Chef and Eid
September Lunchtime 2018 Division 2
Judging Delay, Chef Restaurant
October Lunchtime 2018 Division 2
Three Friends, Coloring the Grid, Weird Question
Code Melange (Rated)
The Deadly Sin, Candy Love
ProCon 2018 (Rated for all)
The Great Run, Kill them with your success
India