Instagram posted a challenge on image unshredding in 2011 around stiching back pieces of an image that has been shredded. My solution for the same can be found in my GitHub repository at Image Unshred.
Project Euler is a series of challenging mathematical/computer programming problems that will require more than just mathematical insights to solve. Although mathematics will help you arrive at elegant and efficient methods, the use of a computer and programming skills will be required to solve most problems.
82 problems by me can be found in my Github repository at Maer.