Joseph's Game of Death, also known as Josephus Displacement, is a common problem encountered in computer programming algorithms, also known as the "Joseph Ring".

Joseph's story goes like this: in the Middle Ages, the Romans occupied Chotapat and forty-one Jewish resisters hid in caves. The Jews decided to kill themselves and sacrifice their lives, and after a while, they decided on a way to commit suicide. Forty-one people formed a circle, starting with the first person, and every time the third person arrived, that person had to commit suicide. Then the next one recounts from 1 until everyone dies by suicide.

This death game is a bit of a fart off your pants. If you really want to die, everyone will kill themselves together. Therefore, the mentality of the participants of the game is either that they are worried that someone will not commit suicide if they are afraid of death, so they want everyone to witness and supervise every death; Either it's a fluke, if everyone else dies and you are lucky enough to stay to the end, you can escape death and surrender generously.

In fact, there are indeed two death-scared cowards in the team - the historian Joseph and his friend, and it was Joseph who proposed the death game.

Joseph, a mathematical genius delayed by history, quickly calculated that the 16th and 31st positions in the circle would be left last, so he and his friends took both positions. When his companions were dead, he and his friends surrendered to the Romans. He complimented Roman commanders on becoming emperors, thus gaining Roman citizenship. Later, as an interpreter, he participated in the Roman invasion of Jerusalem and became a shameful leader of the party.

Regardless of Mrs. Joseph's character, the Joseph problem was introduced into computer programming and is often used as a practice problem in various computer programming language textbooks. Joseph's problem is not difficult, and there are many ways to solve it.

Luo Youcheng believes that if the way to bypass the "Mobius Ring" game is really to use the idea of "Joseph Ring", then it proves that "Uncle and Grandpa" do not want to embarrass his heir. As long as you have a little imagination and happen to hear Joseph's story, you can find a way to clear the level smoothly.

Luo Youcheng said that Pit 31 should confirm his thoughts. The reason why Thirty-One, instead of Pit Sixteen, was chosen because 41-3 Joseph Ring was left to the end at 31 and 16 was the penultimate one.

Liu Ying put forward a different view, if their initial choice was not Pit No. 1, but Pit No. 31 or Pit 16, then they would have cleared the customs directly, which would be too child's play and too anti-intellectual. Luo Youcheng felt that Liu Mei was also reasonable, since Liu Mei entered his body, people seemed to be a little smarter.

It is true that after leaving the back-to-reality game, Luo Youcheng once asked Ah Qing for confirmation on the issue of Joseph Ring.

Ah Qing tells him that if the 41 people in Joseph's death game are considered as N, and the number 3 is considered as M, N and M can be arbitrary integers.

In the game setting, N is a fixed number, which is 41, but M changes with the number of failed levels. Luo Youcheng and the two have failed three times, so M happens to be 3, which is consistent with the number reported in the ancient story. If the number of failures were some other number, the result would certainly not be 31. For example, if you fail 4 times, the number of last out of the ring is 11; failed 5 times, Luo Youcheng should go to jump the No. 22 pit.

This is an afterword, or back to the game scene.

The results of the verification are completely consistent with Luo Youcheng's imagination, the No. 31 pit did not pit him, and the scene here is a study. Su Yuanqing's image sat behind his desk and spoke to his heir. The gist is to push open the back door of the study and clear a very easy mini-game to find a small easter egg.

Liu Ying asked incredulously, "Are you kidding?" It's that simple? ”

Luo Youcheng proudly puffed up his chest, "It's not simple, if it weren't for the fact that I happened to think of 'Joseph Ring' from 'Ring', we would still be jumping into the pit now." ”

Liu Ying thought for a while, nodded, and sent flattery: "Brother Cheng is the smartest." ”

Luo Youwei wanted to communicate a few more words with his "uncle and grandfather", but found that he just said a few words over and over again. What he had in front of him was a very simple image, not intelligence. In other words, legendary NPCs. There are no mission objectives, no hints or hints.

Liu Ying, who had just finished praising Brother Cheng, was dumbfounded again: "What do you want us to do?" ”

Luo Youcheng shook his head helplessly. The two of them walked out of the study and into the back garden. The garden is not big, 300 square meters. At first glance, it looks very beautiful, there are trees, flowers and grass, there are tables and chairs, swings, fish ponds, and weeders.

Liu Ying frowned. The grass grows so tall that it's no longer a lawn, it's a meadow. A few small-leaved ficus trees are covered with dodder seeds, and the branches and leaves are wilting. Dust fell from the table and chairs, and a chair fell to the ground...... In the eyes of Liu Meizi, who loves cleanliness, it is a desecration of beautiful things to abandon a garden with such a good foundation.

Luo Youcheng complained in a coquettish voice: "Leave it alone for now, look for clues." Hey, my uncle and grandfather said it easily, and he didn't even give a hint. ”

Liu Ying also twisted her chubby body, looking around, at a loss. Without knowing the mission objectives, they had no idea where to start. The garden is so big that it is an open space, and at first glance, you can't see anything worth paying attention to.

Liu Ying followed the back of Brother Youcheng's ass for a long time, drilling grass holes, picking flowers, climbing trees and digging holes, but found nothing. She didn't like brain-burning games, so she simply threw a word to Luo Youcheng and ran to weed with a lawnmower herself.

Luo Youcheng didn't find it in the garden, so he pushed open the fence and went into the woods behind the garden. However, this forest is what it looks like, and after walking for less than a minute, it will come to an end, and if you go any further, you can only stand still. Luo Youcheng walked back and forth in the forest along the border at the end, but still didn't find anything.

Luo Youcheng felt more and more strange in his heart. The biggest difference between this little game in the mouth of "Uncle and Grandpa" and other "ring" games is that the sense of reality in the real world has been weakened a lot, it is not so real, and the details are relatively rough. Other games are carefully made, so this small game is in a hurry, and the style does not match at all. He sat in the woods and meditated, puzzled.

When Luo Youcheng came out of the forest, the lawn had been trimmed, and the light and dark strips made the lawn glow again. Liu Ying is removing the cuscus from the ficus microphylla. Luo Youcheng's body is not good at climbing trees, and now she is blessed again, Liu Ying is particularly difficult to climb, but she has no intention of giving up.

Luo Youcheng was inexplicably moved, he ran over and ran up the tree a few times, helping to clean up the parasitic plants on the tree. Liu Ying watched her body jump up and down flexibly under the control of Brother Youcheng, and began to miss her past, the woman who was like the wind.

Liu Ying is a diligent woman, especially like farm work and housework, as long as she is touched by these two things, it is difficult for her to stop if her expectations are not met. Luo Youcheng didn't think about games and easter eggs anymore, so he accompanied Liu Mei to participate in a voluntary labor. Then they trimmed the bushes, repaired the swings, changed the water for the fish pond, reset the tables and chairs, and when they were done, the afternoon passed.

They sat down at the table to rest and looked around the garden, enjoying the sense of accomplishment after their hard work. In a certain situation, labor is also a form of entertainment.

Liu Ying asked: "Brother Cheng, are you still looking for easter eggs?" ”

Luo Youcheng said: "Let's rest for a while and go out, we don't know what to do." ”

"It's a bit of a pity." Liu Ying is lamenting that her curiosity has not been satisfied, and she is also lamenting that her all-powerful brother Youcheng is actually deflated in the game.

"It's been a long time since I've worked, and it's a great feeling." Luo Youcheng is not only comforting Liu Ying, but also comforting himself.

"Huh," Liu Ying said in surprise suddenly, "where did the letter come from?" ”

Luo Youcheng followed Liu Ying's line of sight, and on the white courtyard table, there was an extra letter at some point. It's a very retro setting - write words on paper and put it in an envelope. Centuries ago, when the world went paperless, there was very little paper production, and writing on paper was a luxury. Of course, this is in the game scene, so it can only be said that it is a lofty setting.

This letter should be a little easter egg. Luo Youcheng couldn't believe it, worked all afternoon, and then cleared the customs in a daze.

A few words were written on the envelope: Opened by the teacher (or my heir) himself. "Uncle and Grandpa" didn't seem sure who would see the letter, but he preferred that it would be his teacher Wu Guangxu who came here.

Luo Youcheng took out the letter paper and unfolded it, and the neat brush was covered with paper. The letter reads:

"Dear Teacher (or My Heir)"

"I'm so sorry I played a little joke on you, hard work."

"The easter eggs of the game don't surprise you, it's a nuisance. For three years, I've had a headache about what to do with it. It can be a medicine for the benefit of humanity, or it can be a poison that will lead humanity into the abyss. Unfortunately, the world is being dragged to ruin. By all indications, it has become ubiquitous. I don't know when it will be difficult and how long the world will last......"

The letter is very long, so I won't transcribe them all here. The letter said that Lu Shengcheng was engaged in viromimetic research and was progressing smoothly. Once completed, this project will not only treat genetic diseases, but also be used to prepare a universal vaccine. One more function than what "Uncle Grandpa" mentioned in his memoirs. Virus-mimetic viruses can integrate the envelope glycoproteins of other viruses and disguise themselves as any virus, but it itself has no infectious activity, making it possible to prepare universal vaccines.

Lu Shengcheng happily informed Su Yuanqing of his research findings at that time, saying that he was expected to complete the research within a year, and packaged and transmitted the latest research materials and related data to Su Yuanqing for backup. Two days later, he and his assistant died of murder. Therefore, the information kept by Su Yuanqing is only a "semi-finished product".

This achievement was shelved after Lu Shengcheng's death. It wasn't until later that more and more people began to rush on medical resources, and "Uncle and Grandpa" also got a strange disease, chest pain, and weakness in his left arm, and he sensitively thought of the imitation virus and the group of missing murderers.

If the camouflage ability of the mimetic virus is grafted onto a highly contagious and highly pathogenic virus strain, the consequences are unimaginable. The first thing that came to the mind of "uncle and grandfather" was to "make poison with poison", using a universal vaccine prepared by imitation virus to fight against possible super viruses.

There is a precedent for Lu Shengcheng's murder, and he does not dare to easily hand over the preliminary results of the imitation virus to any virus research team. Virus-like technology is a good knife, a scalpel to save people in the hands of good people, and a good person to kill people. It's a pity that Heng Siliang, the old friend of "Uncle Grandpa" who is most trusted and most likely to achieve a universal vaccine, has died.

The only geneticist he can rely on is Mi Hanliang (Mi Doudou's father and Luo Youcheng's cousin). Mihanliang's main focus is on genetics, and he is lacking in virology research. After reading the research materials, he basically agreed with the guess of "Uncle Grandpa", but it would take him one to two years to complete the later research independently without an assistant.

"Uncle and Grandpa" used the fastest speed to build Mihanliang's exclusive small P4 laboratory, but it was too late after all. Four months later, the two died on their front and back feet. That technology is sealed in P4's private lab. The laboratory is located in the basement of a private farm in Yushi Jin County.

A few months before the end of his life, "Uncle Grandpa" came to the dungeon and temporarily transformed a game scene, leaving clues to the discarded and dangerous research results, and handed over the problem of disposing of this achievement to his successor.

To do this, he set a simple test - a beautiful but cluttered garden. "Uncle and Grandpa" believe that the person who can restore the garden to its original state without any hint must be someone who respects order and rules, can look rationally and can properly handle the virus-mimic technology.

"Uncle and Grandpa" and teacher Wu Guangxu have one thing in common, they love to be tidy and tidy, and they are the most messy, so this test is for other possible successors.

Liu Ying, who has a slight cleanliness habit, uncovered the mystery by mistake.