[dharmon]

We downloaded this last night and my 4-year old has been having a lot of fun working through his 50 or so build options.

We routinely get various lego build books from the library, but it's frustrating how almost every build requires a few critical pieces that we don't have. It'd be cool if this app could tell you if there's some set or kit or odd-lot pieces we could buy that would suddenly make a large number of builds available.

[elephantum]

That's what Lego does.

It seems almost intentional that each set has several rare pieces that can not be found in other sets.

[jacquesm]

You can forget about the 'amost', it is intentional and has been for many years. The time that you could build a model perfectly from the bricks you already had is long gone.

[guepe]

I think that's what make a model such a nice experience. It's different than building yourself: you end-up with something that looks definitely better than an amateur build. You didn't work on imagination, but end-up with an amazing build. Then you can use those unique pieces to put some highlight into your own build !

[castlecrasher2]

>but it's frustrating how almost every build requires a few critical pieces that we don't have

This is to add exclusive value to each set. Look at bricklink.com and find an expensive set, and you'll always find one or two pieces that are a unique color or completely unique to the set that are astronomically high in price. The original Millennium Falcon UCS set for example has two grey (I forget which specific grey) ladder pieces to highlight the engine, and those are the pieces that were most expensive last I looked.

[peteradio]

Thats NP-hard.

[alanbernstein]

I don't think it's NP-hard to identify the individual pieces you need, then show you how to buy them on bricklink.

[yccs27]

But how big is n?