It might be similar to mine: http://pastie.org/2007710 http://pastie.org/2007710 Run on 2.4Ghz Core 2 Duo: $time python oranges.py 7555794 real 1m24.2

It might be similar to mine: http://pastie.org/2007710 http://pastie.org/2007710 Run on 2.4Ghz Core 2 Duo: $time python oranges.py 7555794 real 1m24.252s user 1m23.841s sys 0m0.144s You can still get this to be much faster if you stuff this information into bitmasks, especially if you do it in one of the other languages. You can also get a lot of speedup out of more clever pruning if you're willing to precompute a bunch of stuff. Edit: It seems like a lot of the function calls this program makes are unnecessary. This version runs about 37 seconds faster without any of the trickery I mentioned: http://pastie.org/2007699 http://pastie.org/2007699