Turing Tumble Community

Puzzle 20 – 20 parts

Puzzle Solutions Puzzle 20
#1

The solution:

turing-tumble-20-in-20

And the permalink:

https://www.lodev.org/jstumble/?board=rlerlf1fellfr1felrfrelflrfrelfrreei

In the one case where we need to send the blue ball right to hit the red lever, we know that the bits are afterwards in a position that leads to the interceptor. Hence, we can use the OR gate to replace the crossover and a whole bunch of ramps to get there.

I was trying to build a similar solution for Puzzle 19, but I’m not sure whether it’s fine if one or two additional red ball ends up in the tray at the bottom for some inputs?

3 Likes
Puzzle 19 – 20 parts
#2

Whoa - yep that’s a clear winner so far. Way less parts - nice work! It’s tricky how you send that red ball back through the switches to save parts.

1 Like
#3

You can take advantage of the two crossover pieces to replace 4 ramps. Otherwise, not much to improve here. You need two full paths from the top bit to the interceptor/red release (the former not including the second bit; the latter passing through the second bit). You also need a path from the blue source to the top bit, and a path from the red source to the interceptor, which can’t merge with any existing paths any earlier than the top bit, so there’s 20 components worth of path - crossovers let you cheat that a bit by letting two paths pass through a single component.

image
https://www.lodev.org/jstumble/?board=rlerlf0fellfr0ferlfexferlfexferreei

2 Likes
#4

Ohhh, yeah. I discovered this technique more recently and didn’t think to revisit some earlier puzzles. Feel free to post that in a separate thread.

1 Like
#5

I’m just going through the challenges for the 1st time. This was the same solution I came up with and I was questioning myself because I hadn’t used the crossovers. Gives valid results!