It was only an EXAMPLE. It might be irrelevant to this particular issue, but look at the context of my comment: it isn't irrelevant to the subject of learning to code more efficiently.
I benchmarked the I/O improvement I was thinking about. It actually only resulted in an improvement of about 30%. Worthwhile, probably, but not as "dramatic" as I thought it would be. Mea culpa.
Just a suggestion, but I would also give some thought to efficient coding style, not just algorithms. For example, you could have speeded up your I/O dramatically.
It was only an EXAMPLE. It might be irrelevant to this particular issue, but look at the context of my comment: it isn't irrelevant to the subject of learning to code more efficiently.