A famous mathematician whose first name is Leonard. His last name is X. Google Project X + Problem number will give the website.
This is a fun problem. The main requirement is to write a code in whatever language that can run in less than 1 min and give a correct answer.
The hardest problem I've solved is #269. The harderst problem I've worked hard but not solved yet is #585.
Mathematics behind most problems is very simple. The difficulies are:
- Memory/ calculation speed problem.
- View the problem in a correct way.