Another question: How many times do you need to do this? Why is efficiency so important? If you only need to do it once, just code it, run it, and be done. :D
If you only need to do it once, just code it, run it, and be done.
We need something eficient because with a normal code is just impossible to run with a file of 4Gb! I just don't have 1Gb of Ram to be able to load everything in the memory.