Puzzle challenges!

[Ephraim]

I found another way to solve the problem. Just change the rule:

- If you turn on the center one, it turns on the right line and the top center one too.

- If you turn off the center one, those on the left line and the bottom center turn on.

For this one:

- If you turn on the center one, it turns on the right line too.

- If you turn off the center one, those on the left line turn on.

NOT SURE:

Maybe this one can be a good solution too, but it maybe doesn't works:

- If you turn on the center one, it turns on the right line and the top center one too.

- If you turn off the center one, those on the left turn on.

Note: Starting position = all braziers off.

[Velensk]

You seem to be ignoring the past couple posts. Also, changing rules isn't solving the problem it's just creating a slightly different one.

I'm just going to note, that there are mathematical ways to solve these types of things and if you know those methods it'd be really hard to make a puzzle that's truly difficult. Now there are different ways to solve for it.
--The algorithm that Ravana created will tell you all possible states that could lead to a specific solution.
--I'm inclined to use matrix math to choke out catalogue of moves that leads from the stated start to the stated end which is what you were asking for but is actually far less useful in general.
--There're probably a couple more that I don't know about.
> Now it's worth noting that just because one can turn it into a math problem, doesn't mean that one couldn't try puzzling it out (and find that a funner exercise) but even if you want to try it, you'd often be well advised to run or at least sketch out what the math looks like to begin with to make sure that there is a solution (incidentally, me doing this being the reason why I was pretty confident there was no solution to your original challenge).

If you want to present us with these kinds of challenges, it'd come off better if you looked for the mathematical approaches ahead of time and verified your solution before presenting it. It'll save on moments like your telling me that there was a solution earlier.

EDIT: Clarified one of my comments

[Ephraim]

You seem to be ignoring the past couple posts. Also, changing rules isn't solving the problem it's just creating a slightly different one.

I'm not an expert on codes... so I don't understand a great part of the code explained by Ravana. I just try the methods that are available for my knowledge, just as changing the rules. So, sorry if I have offended somebody with this post.
Anyway, I want to solve the problem that represents this puzzle to be able to give it to other people and make they have a funny moment trying to solve it.
If somebody can explain me how to solve the problem in any way that I can understand (human language) I will be pleased. Thanks.

EDIT: Hmmmm, reading again... I have understood it. The code that Ravana said are the starting positions that I must choose for make the puzzle able to be solved! So... this puzzle is finished yet.
We can use this topic for give other puzzles and people should solve it, as a forum game!

[Ravana]

For the record, the code I made is

Code: Select all

def tostr(board):
	return "%d%d%d%d%d%d%d%d%d"%(board[0][0],board[0][1],board[0][2],board[1][0],board[1][1],board[1][2],board[2][0],board[2][1],board[2][2])

def toboard(str):
	return [
	[int(str[0]),int(str[1]),int(str[2])],
	[int(str[3]),int(str[4]),int(str[5])],
	[int(str[6]),int(str[7]),int(str[8])]
	]
	
def out(board):
	print(board[0])
	print(board[1])
	print(board[2])

def toggle(board, x, y):
	board[x][y] = 1 - board[x][y]

def turn_on(board, x, y):
	if x==1 and y==1:
		# center
		toggle(board, 1, 1)
		toggle(board, 0, 1)
		toggle(board, 0, 2)
		toggle(board, 1, 2)
		toggle(board, 2, 2)
		pass
	else:
		toggle(board, 1, 1)
		toggle(board, 2-x, 2-y)
		toggle(board, x, y)

def turn_off(board, x, y):
	if x==1 and y==1:
		# center
		toggle(board, 1, 1)
		toggle(board, 0, 0)
		toggle(board, 1, 0)
		toggle(board, 2, 0)
		toggle(board, 2, 1)
	else:
		toggle(board, 1, 1)
		toggle(board, 2-x, 2-y)
		toggle(board, x, y)
		
def force():
	states = ["000000000"] # allowed start states
	seen = set()
	while len(states):
		b = states.pop()
		for x in range(2):
			for y in range(2):
				board = toboard(b)
				if board[x][y] == 1:
					turn_off(board, x, y)
				else:
					turn_on(board, x, y)
				if tostr(board) not in seen:
					states.append(tostr(board))
					seen.add(tostr(board))
	print(seen, len(seen))
	# for b in seen:
		# out(toboard(b))
		# print()
	print("111111111" in seen)

def play():
	board = [[0,0,0],[0,0,0],[0,0,0]]
	while True:
		x,y=int(input()),int(input())
		if board[x][y] == 1:
			turn_off(board, x, y)
		else:
			turn_on(board, x, y)
		out(board)
		print(tostr(board))

force()
# play()

[Ephraim]

The holy water:

You enter a small square room. In front of you, stands an imposing solid stone door that is closed.

To your left, there is a fountain from where holy water flows.

To your right you see a kind of large hourglass (sand clock), only without sand and with the lid open. Also note that there are two bowls: one where three units of water fit, and another where five units of water fit.

An inscription shines on the wall:

The poor one will ask for water:
One, three times what he has asked will grant,
(Don't worry, it doesn't matter!),
And another one, a fifth of his goods will give him,
(Here is what you want!).
However, the poor will say:
I only asked for one glass.

What will you do to open the door? How will you do it?
You only have: A fountain of holy water, two bowls, an hourglass ... and your intellect!

Solution and Winner::

Elvish_Hunter solved it.

I'd do the following steps:
Fill the 3-units bowl from the fountain
Pour these three units of water in the 5-units bowl
Fill again the 3-units bowl from the fountain
Pour water from the 3-units bowl into the 5-units bowl until it's filled. Now the 3-units bowl contains just one unit of water
Pour the unit of water from the 3-units bowl into the hourglass

[Elvish_Hunter]

I'd do the following steps:

• Fill the 3-units bowl from the fountain
• Pour these three units of water in the 5-units bowl
• Fill again the 3-units bowl from the fountain
• Pour water from the 3-units bowl into the 5-units bowl until it's filled. Now the 3-units bowl contains just one unit of water
• Pour the unit of water from the 3-units bowl into the hourglass

Did I get it right?

[Ephraim]

I'd do the following steps:

• Fill the 3-units bowl from the fountain
• Pour these three units of water in the 5-units bowl
• Fill again the 3-units bowl from the fountain
• Pour water from the 3-units bowl into the 5-units bowl until it's filled. Now the 3-units bowl contains just one unit of water
• Pour the unit of water from the 3-units bowl into the hourglass

Did I get it right?

Whoa !
You're right. That's the correct answer. How did you find it? (Maybe via uncle Google? )

[Elvish_Hunter]

Whoa !
You're right. That's the correct answer. How did you find it? (Maybe via uncle Google? )

I wish To be honest, I read about this puzzle several years ago, so I already knew it. However, in that version there weren't hourglasses or inscriptions, there was just a scale (I think).

[Ephraim]

Whoa !
You're right. That's the correct answer. How did you find it? (Maybe via uncle Google? )

I wish To be honest, I read about this puzzle several years ago, so I already knew it. However, in that version there weren't hourglasses or inscriptions, there was just a scale (I think).

Hehe
Well, let's change a bit the rules: the person who solve the last puzzle will post another puzzle. If he doesn't know another one, he can just say «I don't know another one», and then, any person can give one, but only the first posted after the solution of the last one will be the official one to solve.

So, do you know any other puzzle, Elvish_Hunter?

[Elvish_Hunter]

So, do you know any other puzzle, Elvish_Hunter?

Right now I don't remember any, sorry

[Samonella]

This is a pretty well known one, but if you haven't heard it before it's quite difficult:

A sailor visits an island that's inhabited by 100 green-eyed dragons. These dragons speak the sailor's language, and the sailor discovers that the dragons are all perfect logicians. However, after a short time, she discovers something unusual: not a single dragon is aware that it has green eyes! Of course they see that all the others have green eyes, so each knows that it probably has green eyes itself, but they do not know it for a certainty.

Additionally, the sailor learns that an ancient spell was cast on the dragons; if any dragon becomes aware that it has green eyes, it will turn to stone at the next dawn! Because of this, the dragons avoid seeing their reflection, and never discuss their eye color. As said, each knows that it probably has green eyes, but none are certain, so none turn to stone.

As the sailor departs for home, intending to return one year later, she muses on the strange creatures. Just before casting off, she calls out a seemingly harmless remark to the dragons: "You know, at least one of you has green eyes!"

One year passes, and the sailor returns. To her horror, she sees that every last dragon has turned to stone.

The riddle is to explain how it happened! Given that the dragons could all see each other's eyes, and given that they are perfect logicians, why did the simple statement that they surely already knew cause each one to become aware of its eye color?

Winner: Ephriam! (After a hint)

[zepko]

Half-serious answer (I did not know the riddle, nor searched it on Google). I don't think it's the expected answer...

Spoiler:

All dragons are color blind, so they see the other dragons' eyes as brown (or at least not green). When the sailor states that at least a dragon has green eyes, each dragon believes it is himself, because he sees every other dragon with a different eye color. So each dragon is aware that it has green eyes, and each dragon turns to stone.

[Ephraim]

Maybe...

Spoiler:

Every dragon wanted to check if he had green-eyes, and asked the other ones for it, so... they turned to stone.

But there is a problem in this answer: "at least one has..." this mean that... yes: it's sure that one had green eyes, but they think: "maybe there are more than one of us that has green eyes!
-"But... how many of us?"
-"At least 99, because you all have green eyes!"
-"What?-I have green eyes? (Puff! Stone)"
-"You have green eyes too!"
-"Really? (Puff! Stone)"

[Samonella]

Good guesses, but both incorrect. The dragons are not color blind ( like I said, good guess though). Also, I mentioned that they never discuss their eye color, and that holds true even after the sailor's statement.

If you want a hint, I can give one that helps but doesn't give it away completely.

[Ephraim]

Good guesses, but both incorrect. The dragons are not color blind ( like I said, good guess though). Also, I mentioned that they never discuss their eye color, and that holds true even after the sailor's statement.

If you want a hint, I can give one that helps but doesn't give it away completely.

I will need the hint...