Some ides to speed up your code:
- Try to use parse instead of split + to!size_t
- Try to use byLineFast, in the attach here (the code is not
mine): https://d.puremagic.com/issues/attachment.cgi?id=1305
- Try to disable the GC before the associative array creation
and re-enable it when it's built. (This could double your max
memory usage or more). To disable it import GC from core.memory
and call GC.disable; and GC.enable;
This code is almost 2.5X faster on my PC (but I am using only
300_000 lines of text):
void main() {
import std.stdio, std.conv, std.string, core.memory;
import bylinefast;
GC.disable;
size_t[size_t] unions;
foreach (line; "input.txt".File.byLineFast) {
line.munch(" \t"); // skip ws
immutable i = line.parse!size_t;
line.munch(" \t"); // skip ws
immutable j = line.parse!size_t;
unions[i] = j;
}
GC.enable;
}
Bye,
bearophile
