Some more solutions.
- Problem 95: Amicable chains
- Problem 63: Powerful digit counts
- Problem 125: Palindromic sums
- Problem 145: How many reversible numbers are there below one-billion?
- Problem 41: Pandigital prime
- Problem 87: Prime power triples
Problem 87 was my 50th problem and I’m now at Level 2 at Project Euler.
In addition to advancing me to the next level, Problem 87 (or rather the gurus who’d solved it before me) reminded me of an important feature of Java Sets… They do not allow duplicates. Very important lesson indeed, since changing solution from List to Set made my solution execute almost 400 times faster 🙂