Project Euler keeps statistics on its users and the problems they’ve solved. Here’s one thing I found interesting. The five most common programming languages used are:
- Python (!)
I am also impressed with the 958 users who are programming in BASIC, the 653 who are using pencil and paper, the 459 who use Pascal, and the 5 users who grew up in a time when they still taught COBOL!
Here’s problem #6:
Find the difference between the sum of the squares of the first one hundred natural numbers and the square of the sum.
Essentially, I’m evaluating:
Because 100 is such a small upper limit, this problem can be solved trivially by brute force. The difference turns out to be 25,164,150.
What’s perhaps more interesting is that there’s an identity for the sum of the squares of first m natural numbers. I found this in the problem notes, which you get access to once you’ve solved a certain problem. The identity is:
That’s new to me!