Subgraph isomorphism is an np-complete problem, and the graph isomorphism problem has not been proved whether it is a p or np problem.
She probably heard something about this in the lectures that Pei Zhi translated.
A staircase divides the building of the Department of Mathematics of Yongchuan University into two halves.
On the other half of the aisle, workers are carrying cardboard boxes and clearing the office.
Lin Zhaoxi looked at it for a while. In fact, she really wanted to find a computer to search for detailed papers on related topics, but now she still had to focus on the defense in front of her.
"Shall we review the defense process again?" Lin Zhaoxi turned her head and said to Old Wang and Ah Guang.
The two looked confused: "How did you change so fast?"
"Because I'm a woman." Lin Zhaoxi replied absently.
Before entering the defense classroom, Lin Zhaoxi was still able to joke with Lao Wang Aguang, but when she pushed open the door of the defense classroom and was shocked by the cold air in the classroom, she understood why Li Ran was crying.
There are two rows of teachers sitting under the stage, but the actual number is not many. But each of them looked serious. In addition, the old campus of Yongchuan University was dimly lit, and most of the windows were covered by creepers, so it was very depressing.
Lin Zhaoxi had expected the difficulty of the defense, so she didn't feel too nervous. After saluting, she inserted the USB flash drive and clicked on the ppt.
"Good morning, teachers, our group number is 205912, and the topic of the modeling competition is b: suspect tracking.
She has rehearsed the content of the keynote speech several times before, so she began to analyze the problem and explain the keynote very smoothly.
After 7 minutes, she finished all presentations.
The audience was silent.
"I recite it very well." After a while, a female teacher looked up and said lightly.
When Lin Zhaoxi participated in the defense of his graduation thesis in the Department of Philosophy, he also received such a comment. However, the expressions and attitudes of their teachers and the current female teacher are completely different when they speak.
Just from the eyes of this female teacher, Lin Zhaoxi could tell that she probably thought that she was here for the prize.
"Because I have been preparing for a long time." She replied seriously.
The female teacher raised her lowered eyelids again, her brows were frowned, and she was very displeased: "Then tell me about your modeling process for the second question."
Lin Zhaoxi took half a step back, letting Old Wang step forward.
"Well, according to Bayesian..."
As soon as Lao Wang's voice sounded, he was interrupted: "What did you say, I will let her answer."
The governess looked stern.
Li Ran probably encountered such a situation just now, so he was too nervous to say a word.
"Wang Tianlong is responsible for the derivation of the overall mathematical modeling part. Lin Zhaoxi paused, "We think it would be more appropriate for him to answer. "
"If you are a member of the group, why don't you understand the modeling formula? Even if you are just an ordinary student in the mathematics department, you should be familiar with the Bayesian formula." The female teacher paused, "You are now in the mathematics department of Sanwei University Your academic level?"
"They are all better than me. I'm from the Department of Philosophy." Lin Zhaoxi replied.
"Although the purpose of the competition does not clearly state that no prizes are allowed, but now anyone can participate in the modeling competition?"
"What are you doing?" Old Wang looked at her and asked suddenly.
"Reporting teacher, the structure of the whole thesis was proposed by Lin Zhaoxi. The mathematics ability of our school's philosophy department is not good, but it is passable. She is my apprentice, and she is planning to take the graduate entrance examination of the mathematics department, isn't it? Grab the prize."
It was rare for Lao Wang to say something seriously, but it sounded like a sarcasm no matter what.
"Since she made the framework of the thesis, why can't she even answer the simplest model derivation?" The female teacher suddenly looked very angry, "The Department of Philosophy crossed the exam for graduate students in the Department of Mathematics? I'm afraid you don't know, mathematics and the humanities you once studied The subjects are different, it requires a lot of solid calculations and hard practice, and all the foundations are in the question I just asked, half-knowledge is not enough!"
"I understand." Lin Zhaoxi picked up the chalk, "Let me answer."
She turned to the blackboard and began to write.
Although there must be a sentence in the strategy, don't conflict with the teacher, but now that this is already done, it is useless to say anything.
The derivation of the overall model is the part that Lao Wang is responsible for, but these are all familiar content for her.
Starting from the basic Bayesian formula, she wrote down all the modeling process, and even carefully completed many omitted parts in the paper.
To avoid being questioned again, she also briefly deduced the algorithm they used.
These contents are actually very basic, not advanced, but all proofs and derivations examine the degree of understanding of the problem.
Finally, facing a whole blackboard with chalk characters, she put down her pen and turned her head.
Pharaoh and Ah Guang's eyes were shining, and they secretly clapped their hands in the place covered by the podium.
The teachers in the audience all raised their heads halfway. Although they didn't speak, their eyes were not as indifferent and careless as before.
On stage and off stage, it seems to be facing each other.
Finally, the female teacher who asked her to answer the question earlier pushed her glasses, as if she had reviewed all the answers, she lowered her head and wrote down a score.
Lin Zhaoxi bowed, packed her things, and prepared to leave.
"Wait, Lin Zhaoxi, right?"
Lin Zhaoxi stopped all movements and followed the prestige.
"The last question is, why did you switch from the philosophy department to mathematics? You suddenly decided to cross the exam in your senior year. Don't you think your life is too casual?"
It was a middle-aged male teacher sitting in the last row of the classroom, with sharp eyes, as if he could see through everything.
Lin Zhaoxi pursed her lips and wanted to answer something, but suddenly she didn't know how to answer.
At that moment, she didn't know what she was thinking, but suddenly wanted to know the other person's answer.
She took out her WeChat, bowed her head, and sent Lao Lin this question under the podium.
"You may think that Mr. Zhang is too strict with you, but in our opinion, your attitude towards mathematics is too easy. You think it is a proud thing to easily jump from philosophy to mathematics with your own intelligence, right?"
"No." Lin Zhaoxi denied.
"Then answer me positively, do you like mathematics?"
"I can't say whether I like it or not." Lin Zhaoxi put the phone back in his pocket, looked up and said, "I didn't choose mathematics, it was mathematics that chose me."
—
Walking out of the classroom and going down the stairs, Lin Zhaoxi passed by workers carrying cardboard boxes.
Why did she switch from philosophy to mathematics? This is a question many people have asked her since she came back from the world for the second time.
For her, it involved too many errands that she couldn't tell others,
But isn't there an answer deep within her
Actually there is.
There is no reason, just because Lao Lin has trained her in this direction since she was a child.
And when she came to the fork in her senior year, she suddenly felt fearful about the future, and just got a chance to start again, e=mc^2 pushed her to another life path.
She just seemed to do that.
"Don't be too sad." Old Wang patted her on the shoulder, bringing her back from a long memory, "It's more common for men in science and technology to look down on girls."
Lin Zhaoxi suddenly wanted to laugh: "Master, aren't you a man of science and technology?"
"I'm different. I don't care whether it's a man or a woman."
"Master, why do you want to learn mathematics?" Lin Zhaoxi asked Lao Wang.
"How can ordinary subjects satisfy the genius who is a teacher?"
"Is mathematics alone enough for you
"Of course, physics is barely okay."
"You are too modest..."
The summer wind blew and the vines swayed, Lin Zhaoxi's mood suddenly improved.
In essence, the male teacher said that to hurt her. In fact, she didn't have to pay too much attention to what these people said.
After all, there's no shame in admitting that you're not the kind of person who inherently knows what you're going to do.
At this moment, her phone vibrated.
Lin Zhaoxi turned on the screen and saw the message she just sent and the answer from Lao Lin.
—Dad, why did you study mathematics back then
— There is no reason, mathematics chose me.
Lin Zhaoxi held the phone and stopped in place.
After that sentence, Lao Lin also sent an emoji of "I am number one in the world".
At that moment, she could almost imagine Lao Lin's wanton and flamboyant face.
His answer was almost the same as hers, but completely different.
Because Lao Lin's answer is the answer that truly belongs to the chosen genius.
Lin Zhaoxi put the phone back in her pocket, and looked back at the defense class just now, feeling regretful.
Among the numerous universes, is there a parallel time and space without her
At the same moment, Lao Lin in that world was one of the professors sitting under the podium and criticizing the students in various ways. A second ago, he had just taken a sip of water, and now he was about to continue spraying.
And in the same way, Lao Lin in that world also fulfilled all his wishes and ambitions and achieved extremely high academic achievements. It is completely different from Lao Lin who has been working around for a long time to earn money to support her in the current world.
It was about that time that Lin Zhaoxi stepped down the last step.
Hundreds of cardboard boxes are lined up under the steps, and a truck is parked beside the building, and workers are moving things.
Stuffed in the cardboard box are countless manuscript papers and archival materials of the Department of Mathematics, most of which are dark yellow and old.
At first glance, it is just an inconspicuous arrangement and relocation, but when you start to guess how many flashes of human thinking will be recorded here, you will still be shocked.
Lin Chao scanned a cardboard box. On the manuscript paper was a mathematical proof deduction that she could not understand very well. At that moment, she saw a string of numbers.
She couldn't tell whether it was a coincidence, or whether the pointer of fate had finally slipped to this moment.
The manuscript paper is titled—Institute of Applied Mathematics, National Yongchuan University.
Below is the address and contact information of the institute—021-57632376.
At that time, she took two more steps before stopping, and then she turned her head in disbelief, walked quickly to the side of the cardboard box, knelt down and checked again.
021-57632376
Due to the long history, the manuscript paper is as fragile as pale yellow moth wings, but the serial number is as bright red as blood.
In Anning City, Cheese World, under a huge camphor tree, she saw Lao Lin dial a series of numbers when she was in fifth grade.
At that time, because of the glare of the sun, she didn't see the last two, so she took it as a destiny arrangement, and didn't do much research in the past.
But at this moment, the sun was as dazzling as that day, and there was no camphor above her head, but the huge puzzle covered her instead of the shade of the tree.
Yongchuan University, Sanwei University... Lao Lin finally gave up mathematics for what
At that moment, Lin Zhaoxi didn't even need any time to calm down. She directly raised her head and asked the workers guarding the box, "This is from the Department of Mathematics of Yongchuan University? What are you going to do? Where are you going to transport the things?"
"Going to the new campus, we are only responsible for moving things, what... don't know anything."
Speaking of this, Lin Zhaoxi was suddenly pulled back, and when she turned her head, she saw Lu Zhihao's puzzled face.
"What's the matter with you, what's the matter?"
Lin Zhaoxi grabbed Lu Zhihao's arm: "Medical students have a five-year program?"
"No, I'm a master's degree holder, and it takes eight years."
"Then your campus card can still be used?" She said, pulling Lu Zhihao to turn around and run away.
"Where are you going, what's the matter?"
"Go to your school library archives."