On Friday, 18 April 2014 at 22:11:17 UTC, bearophile wrote:
monarch_dodra:
Out of curiosity, if the requirement was to *also* preserve
ordering (eg: remove all non-first elements), how would you go
at it?
[2, 1, 1, 3, 2, 3] => [2, 1, 3];
Maybe std.algorithm's `makeIndex` would help here?
Bonus points for doing it inplace.
This preserves ordering and it's in-place. Not tested much:
void main() {
import std.stdio, std.traits;
auto data = [2, 1, 1, 3, 2, 3];
bool[ForeachType!(typeof(data))] seen;
size_t pos = 0;
foreach (immutable i; 0 .. data.length)
if (data[i] !in seen) {
if (pos != i)
data[pos] = data[i];
seen[data[i]] = true;
pos++;
}
data.length = pos;
data.writeln;
}
Bye,
bearophile
I thought of an approach somewhere along these lines. I was
wondering if there was a UFCS approach too. Or an in-place
approach.
Well, the "inplace" is easy of you accept N² performance :)
