On Wednesday, 20 July 2022 at 20:47:28 UTC, ag0aep6g wrote:
(Aside: You don't need that many backticks to mark code
fragments.)
Thought I was following the instructions but it looks like I got
a bit carried away. lol.
You've got a bug there. This should pass, but fails with your
version:
assert(!isRectangular([[1, 2], [], [3, 4]]));
Once `result` becomes false, you cannot let it switch to true
again.
Yeah, I noticed that. I actually fixed it at one point but since
I was having problems scaling whole thing beyond 2D, I thought I
got it wrong.
As for generalizing the function, instead of comparing the
lengths of the elements, you want to compare their "shapes".
The shape of a `Foo[] a1;` is `[a1.length]`. The shape of a
rectangular `Foo[][] a2;` is `[a2.length, a2[0].length]`. And
so on.
[...]
Thank you so much. That was super helpful.
I'm sure the function can be improved further, but I'm not
going to get into that.
For task 3, I can visit each element of the array, but I have
no idea how to compose the flattened (1D) version:
You've got the right idea there with `flatten` calling itself
on each element. You only need to apply that idea when getting
the element type, too (and actually append the result of the
recursive call to `result`):
import std.range.primitives: ElementType;
template FlatElementType(A) if (isArray!A)
{
alias E = ElementType!A;
static if (isArray!E)
{
alias FlatElementType = FlatElementType!E;
}
else
{
alias FlatElementType = E;
}
}
This is pure gold. Thank you.
result ~= flatten(i);
Wow. That simple. I actually printed out the contents of result
and saw the entire thing got was flattened during the recursion,
but for the life of me I couldn't figure out why the final output
always be empty.
[...]
As for task 3, while I understand the concept of transposing a
matrix, I'm not sure how to even begin.
I'm gonna leave that one for someone else.
Thanks again. I really appreciate the assistance.
--anonymouse
