what do you think about "project Euler"? Is it good practice ?

Answer 1

Solving project Euler problems, you will improve your understanding of what happens while algorithms are executing big number of iterations, or dealing with huge numbers, you will learn a lot about code optimisation.
For who enjoy to learn by necessity, challenges in general are a very good school.

Answer 2

It's good to relate some mathematical problems with programming and project Euler does that. It helps you to practice and boosts your confidence.

Answer 3

Actually, it's pure math.

But the interesting point is here: how you use a computer language to solve a particular problem.

Don't forget about one important rule: every Euler problem must be solved within 1 minute after you launch your code. So, heavy codes must be changed into flexible ones. It's where I like it.

So, Euler problems help you not only explore a computer language, but also requires you to bring out short'n'sweet way of execution.