ben
@clews.id.au
Cloud Native Software Engineer in Hobart, Tasmania || Python & Golang || Kubernetes & GCP.
https://clews.id.au/
https://clews.id.au/
Using a HashSet with mathematical generation: ~1.5ms for Part One, ~1.9ms for Part Two.
Instead of brute-forcing, I calculate invalid IDs directly using formulas. The HashSet handles deduplication in Part Two. With early termination and ranges up to 8B+ it's quite fast.
Instead of brute-forcing, I calculate invalid IDs directly using formulas. The HashSet handles deduplication in Part Two. With early termination and ranges up to 8B+ it's quite fast.
December 3, 2025 at 5:19 AM
Using a HashSet with mathematical generation: ~1.5ms for Part One, ~1.9ms for Part Two.
Instead of brute-forcing, I calculate invalid IDs directly using formulas. The HashSet handles deduplication in Part Two. With early termination and ranges up to 8B+ it's quite fast.
Instead of brute-forcing, I calculate invalid IDs directly using formulas. The HashSet handles deduplication in Part Two. With early termination and ranges up to 8B+ it's quite fast.