Hi,
I'm trying to implement counting sort with ranges; however, hit a
roadblock here while testing. I'm using the following code:
int[1_000_000] arr;
void main() {
import std.conv : to;
import std.datetime;
import std.random;
import std.stdio;
for(int i; i < arr.length; ++i)
arr[i] = uniform(0, 1000);
auto benchmarks = benchmark!(algorithmSort,
countingSort)(1);
writeln("Agorithm's Sort: ", to!Duration(benchmarks[0]));
writeln("Counting Sort: ", to!Duration(benchmarks[1]));
}
void algorithmSort() {
import std.algorithm : sort;
auto result = arr[].sort;
}
void countingSort() {
import std.algorithm : count, map;
import std.range : array, chain, iota, repeat;
auto result = 1_000.iota.map!(a => a.repeat(count(arr[],
a))).chain.array;
}
1. `arr[].sort` is changing arr in place. Any way to not do that?
2. I noticed that result within `countingSort` is an array of
arrays. I thought `chain` would concat them... did I miss
something obvious?
3. It's kind of hard to compare performance because of (1), but
is there a better way to do this?
