Yes that's correct, however you need not actually "log that keys i & j have g as a common factor;" if g > 1 then just add x[i] to a list, after checking all in

Yes that's correct, however you need not actually "log that keys i & j have g as a common factor;" if g > 1 then just add x[i] to a list, after checking all in x, then just go through that much smaller list. ( even better would be to just group x[I] in a dictionary based on g)... good example though.