PTYS Chapter 126

“So, this round of the game is Nine Rings, right?” Chen Kaijie said excitedly.

Xiao Muyu nodded, and as soon as she did, the black cloth covering the platform was swiftly lifted, revealing five sets of Nine Rings.

Shen Qingqiu stared at the Nine Rings, frowning, “The first hint was really sinister. Nine zombies and one ring… If it hadn’t mentioned a hands-on puzzle game requiring tools, I wouldn’t have thought of the Nine Rings. And that sudden scare—did it frighten you all?” Although she said “you all,” her eyes were fixed on Xiao Muyu, full of concern.

Xiao Muyu noticed Su Jin glancing at her from the side, so she simply nodded lightly, “Yes.”

Su Jin and Zuo Tiantian, sensing the atmosphere, didn’t say much. Only Chen Kaijie, still shaken, said, “Yeah, this setup is too insidious. I was nervously staring at that small screen, and then those zombies suddenly rushed out from the side, scaring me out of my wits. I didn’t see anything.”

Shen Qingqiu didn’t mock Chen Kaijie; she herself had been startled. But being daring, she had stepped back and swung her blade, realizing it was fake when it missed.

Fear can cloud judgment, but Shen Qingqiu quickly calmed down and saw the information.

Being carefree, once she thought of the Nine Rings, she didn’t bother looking further. Her score was so high that she didn’t care about a 5-point deduction.

Chen Kaijie, a bit embarrassed, said, “I was terrified by the first hint and saw nothing. I didn’t understand the ‘Gray Code’ in the second hint either. It was the numeric poem that made me think of nine, so I guessed Nine Rings.”

Su Jin added, “That poem is rumored to be written by Zhuo Wenjun to Sima Xiangru. The last line is, ‘Nine rings break apart, ten miles of longing.’ I knew the last line, so I wrote Nine Rings. I also didn’t understand the ‘Gray Code.'”

Zuo Tiantian, happy, said, “My college roommate loved playing Nine Rings. I tried it once but couldn’t solve it and looked it up. It seemed very complicated and made my head spin.

But I remembered it mentioned that the solution for Nine Rings is consistent with binary and Gray Code.

I didn’t understand what Gray Code was, but I immediately thought of Nine Rings when I saw it, so I filled it in.”

As everyone shared their thought processes, Xiao Muyu listened intently while moving towards the Nine Rings.

The announcement continued, “Congratulations on correctly guessing this round’s game: Nine Rings. Now for the second phase: skillfully solving Nine Rings! Please listen carefully to the rules:

First: All surviving team members must participate in the Nine Rings challenge, with a 20-minute time limit;

Second: Once started, no verbal guidance, no manual assistance, and no watching teammates’ steps for more than 10 steps, up or down each counts as one step, and all team members must complete the task for the game to end;

Third: Any verbal violation will deduct one minute, manual assistance will deduct ten minutes.

If the game fails, the failing team member will be directly eliminated and become zombie fodder. Note, if a player takes over and fails, both will be eliminated!

Please study how to complete the task, you have thirty seconds for brief communication. Moving the Nine Rings will start the game!”

With these rules stated, everyone’s faces changed, especially with the first rule implying participation was mandatory unless they were dead.

It was essentially a trap to eliminate those who couldn’t solve it, cutting off any reliance on one person solving the task for the group.

But now wasn’t the time to argue the rules. Xiao Muyu quickly said, “Raise your hand if you’ve never played Nine Rings!”

Her words were firm and powerful. Trusting Xiao Muyu, Su Jin and Shen Qingqiu immediately raised their hands without hesitation.

Zuo Tiantian quickly added, “I played but didn’t solve it, over a year ago.”

“I played it in school years ago but can’t guarantee I can solve it in such a short time.”

Xiao Muyu glanced at Shen Qingqiu and Su Jin, both shook their heads, indicating they hadn’t played before.

Xiao Muyu’s face showed a brief, subtle tension but quickly returned to her usual calm.

Due to time constraints, she spoke quickly but clearly, maintaining a composed demeanor that steadied the group.

Chen Kaijie, familiar with Nine Rings, was sweating. Without guidance, first-time players typically took four to five hours. Even those who studied methods often needed thirty to forty minutes on their first try.

Only with long-term practice could someone solve it within ten minutes. The world record was 3 minutes 30 seconds.

“Remember the key points! The goal is to remove all rings, starting from the right, numbered 1 to 9. Su Jin, Qingqiu, watch closely. Rings go up and down through the rod’s middle.

The core rule is: To move a ring up or down, the previous ring must be on, and all rings to its right must be off the rod.

For example, to remove the 9th ring, the 8th must be on, and 1 to 7 must be off. The same goes for each subsequent ring. Understood?”

As Xiao Muyu explained, everyone focused on the blood-red Nine Rings before them, nodding quickly.

“To solve from 1 to 9, you can remove the first five rings in ten steps. I’ll demonstrate the first five slowly, follow my lead.

Those struggling should repeat the first three rings’ steps. Stay calm, don’t rush, trust me.

If you understand Gray Code, remember: 1 means the ring is on, 0 means it’s off. Nine Rings has 341 steps, with the first step’s Gray Code as 111111111, representing step 341 in decimal.”

As she finished, the countdown ended, and the 20-minute timer started.

Without hesitation, Xiao Muyu picked up a Nine Ring set. Su Jin and the others followed suit.

Xiao Muyu demonstrated how to move the rings, stopping after removing the third ring for others to practice.

Her movements were steady and clear. Her determined and encouraging gaze helped calm Su Jin, who initially sweated after hearing Xiao Muyu’s explanation. Gradually, the task seemed less daunting.

Zuotiantian practiced while absorbing the key points that Xiao Muyu mentioned. After completing the third ring with Xiao Muyu’s guidance, she attempted to solve the fifth ring on her own.

Although she struggled, she managed to succeed once and felt she had grasped the trick. Meanwhile, Chen Kaijie, relying on his memory, had already started working on the seventh ring.

As time ticked by, at 2 minutes and 48 seconds, the screen originally displaying the timer began to show numbers. The first set of numbers was 111111111, followed by 111111110, 1111010, and 111111011, repeating over and over.

Shen Qingqiu immediately stopped her actions and began to focus on the numbers. She recognized them as Gray codes, which she had encountered before. She had learned about the conversion between Gray code and binary, though she seldom used it and didn’t expect to encounter it here.

As she practiced with Xiao Muyu, she pondered the implications of what Xiao Muyu had said. Upon seeing the numbers, everything suddenly clicked into place.

Step 340 in binary is 101010100. Converting this from right to left, where 1 changes and 0 does not, the Gray code becomes 111111110. This corresponded exactly to the first step in Xiao Muyu’s solution. Step 339’s Gray code matched the third set of numbers, indicating that both the first and third rings should be down. Then, step 338 indicated the first ring should be up.

Shen Qingqiu, with her sensitivity to numbers, quickly converted these nine-digit binary sequences. Looking at her own Nine Linked Rings, she deduced the current state was 111100000.

With the first five rings down, the next step was to lower the seventh ring, or step 318.

Gray code provided a clear guide for every step, eliminating any guesswork and ensuring the total steps required to solve the Nine Linked Rings was precisely 341, neither more nor less.

As a professional in computer software, Xiao Muyu was intimately familiar with both Gray code and binary. Additionally, she had participated in puzzle-solving competitions during high school, solving similar puzzles blindfolded.

As it became clear that everyone was adept at solving the puzzle, Xiao Muyu’s fingers moved with incredible dexterity. Su Jin and the others noticed that Xiao Muyu’s hands never hesitated, moving seamlessly from one ring to the next.

With the timer approaching 5 minutes, Xiao Muyu still had over thirty steps remaining. Suddenly, a loud bang came from the staircase door on the second floor, shaking the fire door.

All five faces turned pale. What was happening?

Shen Qingqiu kept working while scanning the door. Another loud bang followed, indicating something was trying to break through.

There was no need to guess what might come out in this scenario. Shen Qingqiu glanced at Xiao Muyu, set down the Nine Linked Rings, and approached Chen Kaijie, who handed her a Tang Dao.

Xiao Muyu, holding the Nine Linked Rings, also watched the door. Shen Qingqiu turned her head to Xiao Muyu, smiled reassuringly, and gestured for her to focus on solving the puzzle.

Zuotiantian quickly activated a card to build a wall. Thirty seconds later, a wall appeared in front of the fire door, and she regretted not thinking of this sooner. As the second wall began to form, the door was breached, and zombies began spilling out.

Shen Qingqiu, with her Tang Dao in her right hand and a dagger in her left, swiftly decapitated the first four zombies. She stood at the firewall like a deity of war, while Zuotiantian managed to construct two more walls, partially blocking the door.

One small zombie leaped over the wall as it formed, evading Shen Qingqiu’s defense. Chen Kaijie’s Tang Dao, now dulled from combat, failed to deliver a fatal blow, and the zombie charged towards Xiao Muyu.

Shen Qingqiu, her expression darkening, accelerated and threw her dagger, piercing the zombie’s neck and causing it to collapse inches from Xiao Muyu. Shen Qingqiu kicked the corpse away as Xiao Muyu completed the final ring, the timer stopping at 5 minutes and 59 seconds.

Xiao Muyu, having completed the puzzle in just over three minutes, walked towards Shen Qingqiu. The second door began to shake.

Xiao Muyu frowned, gestured for Shen Qingqiu to continue solving the puzzle, and donned a mask that transformed her appearance into that of Shen Qingqiu.

Although Shen Qingqiu felt uneasy seeing Xiao Muyu in her likeness, she focused on solving the Nine Linked Rings using the Gray code method. She made steady progress, surpassing Chen Kaijie, who was still working on his steps.

Shen Qingqiu’s methodical approach was efficient, but time was running out, and the remaining three had much more to go.

Another bang sounded as the door was hit again.

The author’s note: This serves as a brief introduction to the Nine Linked Rings puzzle and Gray code. Understanding it is not necessary; just enjoy the story. Don’t forget to leave comments; love you all.

Regarding the Nine Linked Rings, the core principle is what Xiao Muyu mentioned. Though beginners might struggle, using Gray code provides a clear solution, requiring exactly 341 steps, avoiding redundant steps.

Converting binary to Gray code helps visualize the ring positions, ensuring no mistakes. However, the conversion can be complex for those unfamiliar with it, and I’m still learning, so corrections are welcome.