The World Machine Think Like A Coder Ep 10
As Ethic falls, she remembers.
She remembers the world before
they unearthed the crystal.
She remembers the glee she felt
when she built her first robot.
But mostly she remembers
the friends she’s made
these last few days:
courageous Adila
and her resistance movement.
Octavia’s sacrifice to keep
the guards distracted.
Lemma and her idealistic
drive to cure everyone.
And Hedge.
Her creation, her responsibility,
her failure… her betrayer.
Hedge, who convinced her to collect
the three nodes
that she never actually needed.
For Ethic remembers how to operate
the World Machine.
If only she could get
a second chance at it.
Adila has been in radio contact
with Octavia,
whom the robots captured and imprisoned
in the same jail that held Ethic.
Ethic explains that Hedge
has manipulated them all,
and will now try to break down
the Bradbarrier
and cover the entire world
in a giant maze,
unless they can stop him.
But she has a plan:
Ethic herself will go
to the crystal at the center of the maze
and use its powers to stop Hedge.
Meanwhile, Adila and Lemma will do
whatever they can to slow Hedge down.
As Ethic weaves her way towards
the innermost maze,
her radio picks up a transmission.
Octavia has freed hundreds of members
of the resistance from stasis.
Together, they’ve staged a jailbreak
and overwhelmed the guards.
The resistance has access
to the World Machine,
but they don’t know how to use it;
they’ll need Ethic for that.
All they have at their disposal
are nearly limitless spools of wire.
The strands are durable, but prisoners
can break them deliberately
if they need to.
Ethic reaches the entrance to the inner
most maze… and it’s sealed from within.
She remembers a few things from
when she flew over the maze days earlier.
It centers on the crystal.
There are many dead ends,
but no paths that loop back on themselves.
Ethic has one opportunity to radio
the members of the resistance
a simple set of instructions
before they plunge into the labyrinth
in search of the exit.
What directions can she give them so
they can quickly navigate the maze,
open the door, and guide Ethic
straight back to the crystal?
Pause now to figure it out for yourself.
Hint in 3
Hint in 2
Hint in 1
Here’s a hint:
One of the challenges here is to find
a way to indicate where dead ends are,
so that the resistance members
don’t keep going down them.
Try simplifying the maze
to something like this.
Let’s say you’ve just hit this dead end,
then came back to this intersection.
What could you do to show the next
person who gets here
that they don’t need
to explore that path?
Pause now to figure it out yourself.
Solution in 3
Solution in 2
Solution in 1
Most programming puzzles involve
giving instructions to a single actor
so that they can accomplish a goal.
Instead, here we have a swarm
of individuals,
each of whom can follow
basic instructions.
That’s unusual in programming,
but not unheard of;
researchers are currently experimenting
with swarms of small robots
to do things like conduct search
and rescue missions.
The prisoners aren’t robots, but for
Ethic’s purposes they’ll act like them.
And by working together they can
achieve their goal much more efficiently.
Because you have a lot of prisoners,
you’ll want them to cover a lot of ground.
This matches up well to a maze-mapping
technique called a depth-first search.
It’s called that because it involves going
as deeply down a path as possible
before going back.
In other words, if you had
a maze like this,
you’d want to explore all the way
down one of these branches
before returning to this intersection
and trying another.
Everyone needs a clear set of instructions
for what they should do.
Like — first, tie down the loose end
of your wire by the crystal,
so it leads back there.
If you find the door,
open it and hand your spool to Ethic.
If you’re in a passageway,
keep going until you hit a dead end
or an intersection.
But what happens
at either of those places?
If someone encounters a dead end,
they should backtrack
to the last intersection.
But they also need to mark it, so no one
wastes time and goes back there.
The best tool for that is the wire—
one option is to break both sections
that lead down the dead end path,
and tie the spool to the wire
that leads back to the crystal.
The broken wires tell everyone else
who gets to this intersection
“Don’t go this way.”
They’ll also guarantee the final path
will lead straight to the crystal,
rather than visiting dead ends.
Ok, so let’s say someone’s
at an intersection.
Now which way should they go?
The first priority is to have everyone
cover fresh ground
to minimize doubling up.
So if there’s no wire down a direction,
go that way.
If there are multiple choices,
choose one at random.
What if they’re in a sub-section
like this, with 3 marked dead ends?
The only thing to do is to go back
where they came from.
We now know that this whole section
is one big dead end,
so they should break and retie the wire
when they get to the next intersection.
But let’s say they get there, and find
two options where someone’s exploring,
but no one’s hit a dead end yet.
They may as well choose at random
and go help explore that path further,
in case it’s the right
direction for the exit.
This isn’t the only way to solve this
challenge, but in any correct method,
someone will eventually
find the way out.
The moment of truth will be when Ethic
takes their wire and follows it back,
inward towards her goal.
The great thing about this method
is that Ethic’s path is straight and true.
The maze doesn’t have loops, so there’s
only one path from door to crystal.
And because everyone has been
breaking and retying their wires,
Ethic won’t go down any dead-end paths.
Face to face with her creation,
Ethic has a choice:
she can destroy Hedge,
or set things right.
All of this destruction was her fault,
not Hedge’s;
it was her oversight that instructed
him to build an infinitely large maze.
His decisions were misguided,
but everything he did,
he did to follow his programming.
Ethic accesses his core and fixes
her error with a single number:
the size the maze was supposed to reach.
Ethic has prevented catastrophe
and regained possession
of the World Machine.
Her work with Adila, Octavia, and Lemma
has already started to help people
and heal the world’s turmoil,
but there’s much work to be done.
With the forgetting food
out of their systems,
the people will become themselves again.
They’ll regain their will to create
and progress.
They’ll be free to break down the walls
they’ve built between each other.
And they may come to approach
their future with a little less greed
and a little more… Ethic