"Refrigerator magnet?" Han Gang raised his eyebrows and said thoughtfully, "Indeed, there are magnets on the back of it, but it is usually either square or round, and it cannot serve as a pointing device at all, unless you can put it in place.
It’s cut into long, thin strips.”
He looked around, shook his head and said: "I'm not very optimistic. There will be sharp and hard tools in this room that can allow you to carefully cut a complete magnet - or if there is such a thing,
If the tools exist, wouldn't it be better if we just use them to unlock and hack the door?"
"Don't think in such a directional way. Although magnets cannot be processed, we can make things that are originally non-magnetic temporarily magnetic." Zhang Ke said as he peeled off a round magnet from the back of the refrigerator magnet.
"You mean - magnetization?" Han Gang's eyes widened and he seemed to understand what the other party was thinking, but he was still a little unbelievable, "The magnetism of such a small magnet is very limited. If you want to use it to magnetize metal,
, only a slender embroidery needle can barely do it, and a slightly thicker iron rod will be difficult to affect."
"It's true that there are no embroidery needles, but isn't there one here?" Zhang Ke picked up the photo album on the table, shook it gently, and shook off all the paper clips on the title page.
"As long as these metal paper clips are stretched and straightened, the width and width will be similar to that of an embroidery needle. Such a long and thin metal needle should be magnetized more easily."
As he spoke, he rubbed the paper clip against the surface of the magnet, always rubbing it in the same direction instead of back and forth. The sizzling friction sound filled the quiet room and became the only sound in the darkness.
It carries all the hopes of the two of them for the time being.
Because there was no timing tool, time became a vague concept that was difficult to calculate. I don’t know how long it took, but Zhang Ke finally stopped when he felt that his arms were heavy and sore, and even the fingers holding the paper clip were a little weak.
hand.
After a long period of polishing, countless fragments of ferroferric oxide powder were scattered on top of the magnet, and the surface of the paper clip was also covered with a circle of magnet powder, making it look dark.
"Is that okay?" Zhang Ke stood up.
Probably because he had been squatting for too long, he walked to the refrigerator with some trembling, and pressed the paper clip against the iron door.
Snap - a crisp sound of adsorption, proving that this paper clip has been magnetized and temporarily acquired magnetism, which means that it can be used as a compass to determine the direction!
"I didn't expect it to actually work." Han Gang finally breathed a sigh of relief, but still refused to admit defeat and said, "That's you, who usually likes to tinker with weird things, but you actually sent it at this time.
Useful."
"It's too early to praise me now." Zhang Ke shook his head and said, "We can't locate it just with a magnetic needle. We need to do some more preparations."
He found the pile of pots and pans from the boxes stacked on the bed, selected a porcelain bowl of suitable size, and placed it horizontally on the table.
Then he took out the white wine he had used to disinfect Han Gang's wounds, filled a whole bowl, and then carefully placed the magnetized paper clip on the water.
"This way, you should be done."
Zhang Ke held his breath and took a few steps back slightly, not daring to breathe out for fear that his breath would blow the sensitive magnetic needle.
Sure enough, the paper clip slowly started to rotate on the water, very slowly, as if it was about to stop at any time, and four eager eyes were paying full attention to every detail.
"It seems to have stopped -" Han Gang covered his mouth and said softly, "it stopped in this direction. It hasn't moved for a long time."
"Wait a minute, wait a minute." Zhang Ke squinted and stared for a while before finally confirming, "If the steps I just took were correct, the direction it is pointing now is probably the south.
"
"The direction that the little magnetic needle is pointing is exactly opposite me, that is, the wall with the number 3. By analogy, the four numbers are arranged in the direction of southeast, northwest, and the resulting password is 3053." Han Gang said.
"The password is confirmed, but aren't we back to the original problem?" Zhang Ke asked, "How do we map the four numbers 3053 to the cipher box with the twelve-digit button?"
"Four digits, twelve digits, the difference between the two digits is three times, and it should not be a simple repeated input. It is indeed a bit difficult to correspond." Han Gang, who has always been conceited, his voice was a little low at this time, and he was deep in thought.
middle.
——On the issue of determining the direction just now, Zhang Ke has been asked to win the first city. Han Gang, who is competitive and thinks he is better than anyone else, is naturally not willing to lag behind others at this time, and is trying his best to crack this code problem.
come out.
"Could it be that each digit can correspond to the up and down states of the three buttons?" Zhang Ke didn't know what Han Gang was thinking, and was still talking to himself:
"For example, assuming that the three buttons are all facing down, it represents 0, the last one is facing up, the other two are facing down, representing 1, the middle one is facing up, and the other two facing down represent 2... and so on, maybe 3053 can be converted
It’s a twelve-digit button code, but I’m just talking nonsense about this rule, and there’s no solid basis for it—”
"Wait, what did you just say?" At this moment, Han Gang's body suddenly felt like an electric shock. He suddenly raised his head tremblingly, stared hard at Zhang Ke's face, and reiterated, "Repeat what you just said.
Once again!"
"I mean... if you can use the up and down states of buttons to represent numbers from small to large, wouldn't it be possible - "
At this point, even Zhang Ke himself suddenly paused. He finally realized why Han Gang was so surprised just now!
"It's binary conversion!" The two of them reported the answer almost at the same time.
Zhang Ke may not have realized just now that the conjecture rule he mentioned is actually the process of converting decimal numbers into binary.
Set the upward state of the button to 1 and the downward state to 0, then 000 is zero, 001 is one, and 010 is two in decimal. This is common sense that everyone knows, but I just casually
I didn't even notice it when I said it.
The buttons on the lock box can only be pressed down or stay up, and there are no more changes. Therefore, the password to unlock this lock must be some special arrangement of the up and down states of these buttons——
In other words, it is a sequence of binary numbers.
More importantly, if a four-digit decimal number of about three thousand is converted into a binary expression, the final result may indeed be as long as more than ten digits.