February Challenge 2015
Chef and Strange Formula, Chef and Strings, Let us play with rank list, Chef and Equality, Chef and Chain
December Challenge 2015
Oracle Devu and Longest Common Subsequence, Tanks, Chef and Girls, Chef and Filters, Misha and Permutation, Plane Division, Chef and the stones, Chef and cinema, Sereja and Dividing
January Long Challenge 2016
Rupsa and the Game, Devu and Perfume, Chef and Time Machine, Cyclist Race, Chef and Making Triples, Churu and Balls, Chef and Inflation, Sereja and Salesman
March Challenge 2016
Sereja and Two Strings 2, Chef And Hungry Birds, Palindromic substrings, Floor Distribution, Chef and Number Guessing, maximize the sum, Parity tree, Chef And Special Dishes
April Cook-Off 2016
Movie Weekend, Odd Divisors, Queries on a Binary Tree
Bangladesh