It largely depends where the bottleneck is. In this case it may be the algorithms and data structures chosen if the two implementations are equivalent in that r

It largely depends where the bottleneck is. In this case it may be the algorithms and data structures chosen if the two implementations are equivalent in that respect. I would highly doubt any C++ implementation using a reasonably efficient implementation (avoiding quadratic algorithmic complexity) that only works on a local file of modest size would take anywhere near 800 seconds on any modern machine.