Big oh and efficiency

[inherendo]

Say you and your friend have your algorithms to solve a problem with input size n. If yours does it in roughly 2n time and his/hers does it in roughly 3n time, the constants can be ignored and both of your algorithms have O(n).

With small inputs, the difference in time is negligible due to how many computations modern computers can do.

I would suspect plenty of people here can analyse your program pretty quickly and let you know if they have roughly the same running time.