On Friday, 18 April 2014 at 22:11:17 UTC, bearophile wrote:
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
If you replace that "=" with a swap, then you can also preserve
the duplicate elements at the end (although in no specific
ordering):
import std.stdio : writefln;
import std.algorithm : canFind, swap;
//----
void main()
{
auto arr = [1,1,5,2,3,2,2,4,5,5,1];
size_t pos = 0;
foreach(ref e; arr)
if (!arr[0 .. pos].canFind(e))
swap(arr[pos++], e);
writefln("uniques: %s", arr[0 .. pos]);
writefln("dupes: %s", arr[pos .. $]);
}
//----
I was trying a "100% inplace" solution, but I found nothing
better than N². It's basically still what you submitted though.
