線形符号

app.d

import std.stdio : writefln, writef;
import std.format : format;
import std.conv : to;

void main(string[] args)
{
    long L = args[1].to!long();
    auto fmt = format!"%%0%db"(L);

    outer: foreach (c_bitmask; 1 .. (1 << (1 << L)))
    {
        foreach (ulong x; 0 .. (1 << L))
            if (c_bitmask & (1 << x))
                foreach (ulong y; x .. (1 << L))
                    if (c_bitmask & (1 << y))
                    {
                        if (!(c_bitmask & (1 << (x ^ y))))
                        {
                            continue outer;
                        }
                    }
        foreach (ulong x; 0 .. (1 << L))
            if (c_bitmask & (1 << x))
                writef(fmt ~ " ", x);
        writefln("");
    }
}