Escape the Library

The course "Prime Number Labyrinth" in the School of Mathematics allowed the four people in the research group to get up to 585 points, which is higher than the previous "Cardiovascular Ward", and they only spent an hour and a half for so many points!

Thinking of the five-day thrilling experience of finding a murderer and fighting monsters in "Cardiovascular Ward", this time I got 585 points in one and a half hours, which is really easy.

Yue Xingwen was excited, turned around and gave Jiang Pingce a hug: "full score, you are really awesome! The three of us are just running errands, and we can get 585 points, so comfortable!"

Liu Zhaoqing said with emotion: "This should be the easiest time for us to get points, right? There is a scholar in the team, it's like a plug-in."

Ke Shaobin also said seriously: "Even if I get a calculator, it probably won't be as fast as Pingce's mental arithmetic."

Yue Xingwen has always known that Jiang Pingce is very good at mathematics. In high school, Jiang Pingce scored full marks in every test in mathematics. It is said that the math teacher in their class will directly use Jiang Pingce's paper as the standard answer to give a question.

When he got to the university, Jiang Pingce was even more powerful. This time the maze combined mathematical operations and three-dimensional geometric figure analysis. Without Jiang Pingce, they would not have walked out in 1.5 hours, and they might not have found their way in 4 hours.

Yue Xingwen patted Jiang Pingce's shoulder lightly, and said with a smile, "Major hero, you have worked hard for you this time."

Jiang Pingce said: "It's okay, it's not hard."

After taking the first course, the time in the library is ten o'clock in the morning, Yue Xingwen glanced at the clock on the wall and said, "Let's go back to the dormitory first, Senior Brother Zhuo Feng and the others should go to retake the medical school courses soon. Out."

When the four of them went out, they returned to the hall of the School of Mathematics. Many students gathered under the big screen of the class schedule. The students were all frowning, obviously not knowing how the School of Mathematics should pass the test.

Yue Xingwen glanced at the bewildered classmates, lowered his head and thought for a while, leaned into Jiang Pingce's ear, and said softly, "The failure rate of the "Maze of Prime Numbers" in the Mathematics School is as high as 65%. It seems that Many students are stumped. If you don’t mind, why don’t you share our customs clearance strategy with everyone and help them?”

Jiang Pingce simply agreed: "Okay, I'll go back and sort out my thoughts."

They have already passed the exam, and sharing the strategy with the students behind them has no impact on their own performance, just like many senior classmates in the university will share their experience and provide review materials with their junior brothers and sisters.

Yue Xingwen has received the help of many brothers and sisters in school, and he himself often shares information on the forum.

Jiang Pingce never did this. But nowadays, the library is different from reality. If you fail the subject, you will have to rebuild it. If you fail again, you will die! Since Yue Xingwen called for the establishment of a college alliance, Jiang Pingce was of course willing to cooperate with him and share his experience, so that the following students could pass the test more easily.

The two returned to the dormitory, and Jiang Pingce began to organize the maze map.

He redrawn the maps on the upper, middle, and lower floors, took pictures and uploaded them with the tablet computer that came with the dormitory, and then posted a post on the forum—

[Mathematics College "Prime Number Maze" course clearance strategy]

Jiang Pingce's strategy post is very concise, using the black Song typeface that comes with the forum. Like a math problem, he simply listed a few points.

1. Don't want to do additional questions, just ask for the passing method of the team with a passing score of 60 points:

The prime number maze is a three-dimensional structure. After entering the maze, you can ignore all the numbers in the room. You don't need to calculate whether it is a prime number. Simply use the number on the door as the number, and draw a route while walking. Go back every room, first right, then left, find the elevator on this floor as fast as you can, and go up/down.

The upper and lower floors of the maze are 7x7 with a total of 49 rooms. Draw a total of 49 square grids with 7 horizontal and 7 vertical on the paper. Go straight to the end in any direction, turn right or left and continue until the end, that is, walk one. "L"-shaped route, at this time, you will be in a corner of room 49, and then follow the "s"-shaped route to check, you will not take repeated paths and get lost.

After finding the elevator, go out of the maze, the course is completed, and the score is 60.

The detailed three-layer plan of the maze, the synthesized three-dimensional graphics, and the maze route map are attached for reference. In the next exam, there may be some changes in the interior of the maze, and the numbers will definitely change, but the overall structure and clearance ideas will remain the same.

2. How to pass the test for teams who want to do additional questions:

The additional problem requires collecting all twin primes, so it is necessary to search all the rooms in the maze and calculate whether each number is a prime number. The mantissa 1/3/7/9 is more likely to be a prime number, and the mantissa 0/2/4/5/6/8 is directly excluded.

1. Quickly determine whether a number is divisible by 3: add each digit of the number, if it is divisible by 3, it can also be divisible by 3. For example, the number 185337 can be directly calculated as 1+8+5+3+3+7=27, 27 is divisible by 3, then 185337 is also divisible by 3, this number is not a prime number.

2. To quickly judge whether a number is divisible by 7, 11, and 13, you can use the "last three method". Divisible by 7, 11, and 13.

Example: 939911, can be divided into 939-911=28, 28 can be divisible by 7, then 939911 can also be divisible by 7.

For example; 124371, can be divided into 371-124=247, 247 can be divisible by 13, then itself can be divisible by 13.

The addition method and the last three methods are all to reduce the number of digits and simplify the math-operation.

The proof is as follows:

Let a number be abcdef.

abcdef=abcx1000+def=abcx1001-abc+def=abcx7x13x11-(abc-def)

When abc-def is divisible by 7/11/13, then abcdef is divisible by 7/11/13...

Seeing this, Yue Xingwen had given up thinking because of a headache, and the content that followed was swiped directly with his fingers.

Mathematics is indeed an amazing subject.

Jiang Pingce's strategy is serious and rigorous, not only telling everyone what to do, but also "why do it". Science students don't seem to have any difficulty, but liberal arts students are really dizzy.

After Jiang Pingce posted the strategy, the number of replies soared immediately.

Many brothers and sisters majoring in liberal arts left messages one after another: "Xueba, my roommate asked me why I was kneeling to see your strategy!"

"How can I have the confidence to click on the guide post of the Math Academy? I want to poke my eyes."

"My eyes tell me it understands, but my brain tells me it doesn't understand!"

"What do you think about the liberal arts students? The courses in the mathematics college are just passable. Can you just read the first one? This senior brother even drew a map, and the first one is quite easy to understand. As for the second one... I I'm sorry for skipping it."

"You're right upstairs, extra questions? Think too much. Don't do extra questions, just ignore all the numbers, just walk through the maze and burn the incense if you can get out!"

Many science students said that their thoughts were finally clear after reading the post, and they expressed their gratitude to Jiang Pingce who took the initiative to post the strategy, and many fans and sisters confessed to Jiang Pingce in the post.

The replies were mixed with a lot of "Senior brother is so handsome", "Xueba", "Male god, do you still lack leg pendants".

Yue Xingwen couldn't help but chuckle, looked back at Jiang Pingce, and joked: "As soon as you post this strategy, it is estimated that you will gain a large number of fans in the library, and I have seen dozens of replies to your confession. one."

Jiang Pingce said lightly: "If you hadn't spoken, I wouldn't have written this strategy."

He was never a warmhearted person, but he never refused Yue Xingwen's request. He will help whoever Xingwen asks him to help. If Yue Xingwen didn't say it, he wouldn't spend time actively posting any tips.

Yue Xingwen knew that Jiang Pingce had such a cold and indifferent character, and when he heard this, he smiled and walked over to sit side by side with Jiang Pingce, and said, "Although some people can't understand your strategy post, there are also a large number of classmates who can Learn from it, at least after you understand the first one, you can walk out of the maze smoothly and get a passing score of 60.”

He turned his head to look at Jiang Pingce and said softly, "Pingce, writing this guide is just a small effort for you, but it is like rain in time, and it can solve the problem that many research groups cannot overcome the prime number maze."

Yue Xingwen's expression was serious: "Don't think I'm nosy and good-natured. The environment in the library is too cruel. Just now, under the timetable screen in the hall of the School of Mathematics, several girls were crying anxiously. It's easy for you. The labyrinth of prime numbers may cause many students who are not good at mathematics to sleep well, or even be eliminated. Let's just help, how many can we help, what do you think?

Every time he talks to people seriously, he can always persuade them.

The corners of Jiang Pingce's lips raised slightly: "Well, listen to you. In the future courses, we can also organize the exam strategies and give them a reference." He looked at Yue Xingwen beside him, his eyes gradually softened , "You always like to help others. With you in the library, the overall difficulty has been reduced a lot."

Whether it is to formulate a student agreement to restrain everyone and prevent teammates from fighting with each other; or to take the initiative to send out strategies to give students more reference ideas for later exams...

Yue Xingwen's approach has been helping students.

It was he who made the atmosphere of the entire library harmonious and warm.

The original dark and thrilling escape game turned into a college final exam of "students work hard together".

From the replies on the forum today, it can be seen that many of the classmates responded in a lighthearted and humorous way, and some of them even dared to tease Jiang Pingce in their posts, just like flooding and chatting in the school forum. Compared with the large-scale abuse and quarrel caused by the acid throwing the day before yesterday, the forum in the library has gradually become more energetic and warm.

Yue Xingwen was too embarrassed to be praised, and coughed lightly: "Don't put a high hat on me, I'm just doing what I can, this maze is thanks to you. I only now understand what the map you drew is. I mean, it's really amazing, if I were to analyze it myself, I couldn't think of a 7x7 grid, and I would have been dizzy long ago."

Jiang Pingce said warmly: "My sense of space and computing skills are indeed better than yours, but your language skills and knowledge are much better than mine. Everyone has their own strengths, so don't be ashamed because you can't compare with mathematics. "

Yue Xingwen raised his eyebrows: "How can I be ashamed? With you here, if I encounter mathematics in the future, I will just give up thinking!"

The two smiled at each other.

On the forum, Jiang Pingce's post quickly became popular.

As Yue Xingwen said, this guide post is like a timely rain in the hot summer for the team trapped in the Mathematics Academy on the second floor. If you don't do additional questions, just pass the test, and follow Jiang Pingce's method to walk the maze, even a team of four liberal arts students can pass the test with 60 points. Students with strong computing ability can try to do additional questions, and Jiang Pingce listed many skills for them.

There are more and more messages of thanks, and some younger brothers and sisters recognize Jiang Pingce's name and pay homage to Jiang Pingce, the legendary **** of mathematics in the department.

Jiang Pingce glanced at the message and closed the forum.

This is the first time he has shared his experience with other classmates since he grew up.

In the three years of high school, because he was too indifferent, no one dared to borrow notes from him. When he arrived at the university, he was a loner and rarely communicated with his classmates except for the occasional self-study with Yue Xingwen.

After the strategy post was posted, Jiang Pingce suddenly felt that he was in a good mood when he saw a large number of "thank you" in the thousands of replies. He used to think that Yue Xing Wen loved tossing, but now he realized that only Xing Wen, no matter what kind of world he faced, was in a good mood. , can maintain a kindness and a pure heart.

Such people are the rarest.

Seeing Jiang Pingce keep looking at himself, Yue Xingwen couldn't help but wonder: "What's the matter, am I wrong?"

Jiang Pingce smiled lightly: "What you say is right."

Yue Xingwen patted the other party's shoulder, with a proud expression of "count you wise". After a pause, he said sternly: "Let's not go to the elective courses this afternoon? I have a headache looking at the class schedule, so I'll talk about the compulsory courses first."

Jiang Pingce nodded: "Well, I will rest in the dormitory in the afternoon. There will be a compulsory course "Death Code" in the math college at 8 o'clock tomorrow morning. Let's go directly to this course."

Yue Xingwen thought thoughtfully: "Death code? Listening to the name sounds like a reasoning class?"

Jiang Pingce guessed: "It may be a suspenseful case related to numbers."

The two looked at each other, and Yue Xingwen smiled and said, "If it's a reasoning class, I can still help. At that time, let's complement each other's arts and sciences, clear customs together, and try to get more points to upgrade my dictionary!"