March 2012 Challenge
Free Shuttle Service, Spoon in Matrix
April Challenge 2012
Fit to Play, Double Strings, Greatest Dumpling Fight
May Challenge 2012
Jewels and Stones, Lucky lucky number, Remember the recipe
June Challenge 2012
Little Elephant and Candies
August Challenge 2012
Little Elephant and Bombs, Delivery Boy
January Challenge 2013
The Minimum Number Of Moves, Three Different Numbers, Chef of the Year
April Challenge 2013
Maximum Weight Difference, Levy Conjecture
May Challenge 2013
Witua and Math, Name Reduction, Your Name is Mine
February Challenge 2014
Longest Common Pattern, Little Elephant and Subarrays
May Challenge 2017
Chef and his daily routine, Courses in an university, Median of adjacent maximum numbers
May Challenge 2020 Division 2
Coronavirus Spread, Isolation Centers
Costa Rica