February 2012 Challenge
Lucky Count, Lucky Long, Word Couting, Count of Maximum, Box and Ball System
March 2012 Challenge
Free Shuttle Service, Home Delivery, Spoon in Matrix
March Cook-Off 2012
Ciel Numbers I, Ciel Numbers II
April Challenge 2012
Stacking Pancakes, Similar Graphs, Greatest Dumpling Fight, Double Strings, Fit to Play
May Challenge 2012
Killing Gs, Little Elephant and Median, Jewels and Stones, Lucky lucky number, Divisible Pairs, Remember the recipe, A Home for Chef
June Challenge 2012
Little Elephant and Product, Arranging Cup-cakes, Doom Bakes Cakes, Closest Points, Little Elephant and Candies
July Challenge 2012
Chef's Dream, My Fair Coins, Gift Rift, Restaurant Rating
September Challenge 2012
Kisses & Hugs, Racing Horses
October Challenge 2012
Maximum Sub-rectangle in Matrix, Need More Diamonds, The New Scheme, Event Organizer, Fierce Battles, Little Elephant and Order
October Challenge 2019 Division 1
Even Edges, Chef and Maximum Star Value, Array Modification, (Challenge) Maximizing LIS
November Challenge 2019 Division 1
Physical Exercise, Smallest Beautiful Number, From Zero to Infinity, A Simple Game, Single Point of Failure
