Provide your first answer ever to someone else's question

Awarded to Alexander on 31 Jul 2020

Like a problem or solution

Awarded to Alexander on 22 Dec 2014

Comment on a problem or solution

Awarded to Alexander on 12 Feb 2019

Solve a problem for the first time

Awarded to Alexander on 11 Dec 2014

Solve 500 problems

Awarded to Alexander on 24 Jul 2018

Solve a problem with a best solution

Awarded to Alexander on 12 Feb 2019

Be the first to solve a problem

Awarded to Alexander on 16 Nov 2016

Create a problem

Awarded to Alexander on 23 Nov 2016

Solve all the problems in ASEE Challenge

Awarded to Alexander on 24 Dec 2014

Solve all the problems in Cody Challenge

Awarded to Alexander on 28 Jan 2015

Solve all the problems in CUP Challenge

Awarded to Alexander on 22 Dec 2014

Solve all the problems in Indexing I

Awarded to Alexander on 16 Nov 2016

Solve all the problems in Indexing II

Awarded to Alexander on 09 May 2018

Solve all the problems in Indexing III

Awarded to Alexander on 18 Jul 2018

Solve all the problems in Magic Numbers

Awarded to Alexander on 21 Nov 2016

Solve all the problems in Matrix Manipulation I

Awarded to Alexander on 12 Feb 2019

Solve all the problems in Matrix Manipulation II

Awarded to Alexander on 07 Feb 2020

Matrix Patterns I Master

Awarded to Alexander on 08 Jan 2020

Solve all the problems in Number Manipulation I problem group

Awarded to Alexander on 08 Jan 2020

Solve all the problems in Strings I

Awarded to Alexander on 09 Jan 2020

Solve all the problems in Tiles Challenge

Awarded to Alexander on 24 Dec 2014

Solve all the problems in Draw Letters problem group

Awarded to Alexander on 06 Dec 2019

Solve a community group

Awarded to Alexander on 12 Feb 2019

Solve all the problems in Introduction to MATLAB problem group

Awarded to Alexander on 12 Feb 2019