23 Oct
2007
23 Oct
'07
6:15 a.m.
jerzy.karczmarczuk@info.unicaen.fr writes:
1. Avoid two pass filtering. 2. Avoid unecessary (++), with an accumulator. For example:
Also, I find that 3. Accumulate equal elements, too pa (y:ys) s e b = case compare x y of ... to be a good choice. Otherwise, quicksort easily grows towards quadratic if you have many multiples of the same value. I think this is more common than the other major pitfall, sorting an already sorted list. (But perhaps the three-way case based on 'compare' is more expensive than the two-way (<) test?) -k -- If I haven't seen further, it is by standing in the footprints of giants