Chapter 158 Plan

In December, Huizhou was hit by its first snowfall of the year without warning.

Chen Zhuo walked towards his dormitory with his hands in his pockets, following the path from the Faculty of Science.

He had just come out of the conference room in the Department of Mathematics.

In the afternoon, he and Wu Tao spent four hours in front of the blackboard deriving the convergence domain. Although they managed to build the bridge in the end, the intense mental exertion made his temples throb.

With final exams approaching, at this time of year, most people are either reserving seats in the library or cramming into their textbooks in the study room.

As Chen Zhuo went up the stairs to the second floor, he saw Wang Dayong leaning against the door frame of room 216.

Holding a roasted sweet potato she had just bought from an oven outside the school, she peeled off the skin while peering intently through the crack in the door, a knowing smile spreading across her face.

"Dayong, what are you doing?"

Chen Zhuo walked over and called out softly.

Wang Dayong turned around and saw that it was Chen Zhuo. He quickly swallowed the sweet potato in his mouth and lowered his voice to say something.

"Xiao Zhuo, come quick! Lu Jia's got a big surprise up his sleeve here."

Chen Zhuo peered through the crack in the door.

Lu Jia stood with his back to the door in front of a whiteboard that had been moved from somewhere.

He held a black whiteboard marker in his hand and was drawing on the whiteboard with an extremely rigorous academic posture.

On the left side of the whiteboard is a simple but precisely proportioned planar coordinate diagram.

The sign above reads: Old Library, Physics Building, Third Canteen.

To the right of the whiteboard was a densely packed collection of mathematical formulas.

Chen Zhuo pushed open the door, and Da Yong followed him inside.

Lu Jia was completely focused and didn't notice that there were two more people behind him.

He was pointing at several coordinates on the whiteboard with the tip of his pen, muttering to himself.

Chu Ge sat in a swivel chair by the window, a lollipop dangling from his mouth as was his habit.

He crossed his arms, his long legs resting on the edge of the computer desk, and was looking at Lu Jia with the eyes of someone looking at an alien. "Don't worry about my hash algorithm for now."

Lu Jia pushed up his glasses that had slipped down his nose, turned to look at Chu Ge, and looked as serious as if he were giving a research proposal.

"What we need to solve now is the problem of encounters in the real dimension."

Chu Ge rolled his eyes, turned the lollipop in his mouth around so the stick curled up at the corner of his mouth.

"Alright, Professor Lu, please continue."

Chu Ge shrugged.

Lu Jia turned around and used a whiteboard marker to draw a line with an arrow connecting the old library and the third canteen.

"After two weeks of undercover observation, I found that my senior's daily routine is extremely regular."

Lu Jia wrote down a time period next to the connection.

"Every Monday, Wednesday, and Friday afternoon, she would definitely study in the foreign language reading room on the third floor of the library in the north, and she would leave between 4:45 pm and 5:10 pm."

Lu Jia drew a standard curve for that time period.

"This is a very typical normal distribution."

Lu Jia tapped the apex of the bell-shaped curve with his pen.

"4:57 is the peak of probability density, which means that if I appear in the lobby on the first floor of the library at 4:57 every day, I have a 68.2% probability of seeing her coming downstairs."

But that's not enough.

Lu Jia shook his head and wrote a new formula on the whiteboard.

"If we bump into each other in the library, we can only nod and smile, lacking a proper opportunity to start a conversation. The best scenario is when we're queuing in the cafeteria."

Lu Jia took a deep breath, his eyes revealing absolute confidence in mathematical tools.

"I introduced a Markov chain model to calculate the probability of her dietary preference shift."

Lu Jia drew three state nodes on the whiteboard and labeled them A, B, and C respectively.

"State A is the congee on the second floor, state B is the rice bowl on the first floor, and state C is the spicy hot pot on the third floor. We know that she was in state B on Monday and moved to state A on Tuesday. Based on the sample data I collected over the past two weeks, the probability of moving from state A to state C is 0.4." Lu Jia quickly marked the decimals between the nodes.

"The temperature dropped sharply today, and it snowed in Huizhou. Based on the negative correlation between temperature and calorie intake requirements, I increased the weight of state C by 0.15. Therefore, the overall probability that she went to the third floor of the third canteen to eat spicy hot pot today is as high as 72%."

Lu Jia turned around, her eyes shining as she looked at Chu Ge and Wang Dayong and Chen Zhuo, who were standing at the door.

He seemed indifferent to the two extra people, or rather, he desperately needed an audience to validate his theory.

"The final step is the step rate equation."

Lu Jia wrote a speed formula at the bottom of the whiteboard.

"The senior student's average walking speed is 0.9 meters per second. If she leaves the library at 4:57 and goes to the third floor of the third canteen, I only need to leave the second teaching building at 4:59 and enter the main road at a constant speed of 1.2 meters per second. I can then stand right behind her at the corner of the stairs from the second to the third floor of the third canteen."

Lu Jia capped the whiteboard marker and let out a long sigh of relief.

"With an error margin of no more than two seconds, at this point, all I need to do is say very naturally: 'What a coincidence, senior, you're here for hot pot too?' This opening line is absolutely perfect."

The dormitory was silent for a full ten seconds.

Wang Dayong took a bite of the roasted sweet potato in his hand, swallowed it, looked at the formula on the whiteboard, then looked at Lu Jia, a simple blank expression on his face.

Chu Ge let out a very short laugh.

He put his legs off the table, slid his swivel chair forward, and moved closer to the whiteboard.

"Lu Jia, you can't even be flexible enough."

Chugo reached into his mouth and took the lollipop out, pointing with the stick at the pile of Markov chain formulas.

"You're calculating normal distributions and state transition matrices here just to chase after a girl? What do you take human behavior for? A random number generator?" Chu Ge leaned back in his chair, shook his head, and said with a hint of exasperation at Chu Ge's lack of ambition.

"Using algorithms to calculate probabilities to address this need is the dumbest and least efficient method."

Lu Jia frowned.

"Do you have a better empirical model?"

"Empirical proof my ass."

Chu Ge chuckled.

"You want to check her dietary preferences? What kind of transfer probability are you talking about? Wait for me for half an hour."

Chu Ge turned around and placed his hands on the keyboard.

"The POS card reader in the school cafeteria transmits data back to the server in the logistics network center every night at 0 p.m. That broken server uses the Windows NT system and doesn't even have a proper firewall; it relies entirely on physical isolation via the local area network."

Chu Ge's fingers unconsciously tapped twice on the keyboard.

"I only need to write a simple packet capture script to disguise myself as a terminal node in the cafeteria and intercept the packets when it synchronizes data. As long as you tell me her meal card number or her student ID, I can access the database in ten minutes and find out whether she ate rice bowls on the first floor or porridge on the second floor in the past two weeks. I can even give you a list of whether she added braised eggs or not."

Chu Ge turned his head and looked at Lu Jia.

"Why are you building a probability model here when you have readily available underlying data?"

Lu Jia was stunned by Chu Ge's simple and brutal explanation of the Internet's dimensional reduction attack.

He opened his mouth, attempting to refute the argument from a moral and legal standpoint.

"This...this constitutes illegal intrusion into the campus network, it's a very serious offense. What if the network management center catches us..."

"If they catch them, it's on me."

Chu Ge waved his hand dismissively.

"Technical methods are always more direct than theoretical derivations."

"You two are just wasting your breath."

Wang Dayong, who had been leaning against the door frame eating sweet potatoes, finally couldn't take it anymore.

He threw the last piece of sweet potato peel into the trash can by the door and dusted off his hands.

Dayong walked up to the whiteboard, looked at the complicated connections, and curled his lip in disapproval.

"Lu Jia, listen to my advice. If you want to woo a girl, all this fancy formulas and codes are useless."

Da Yong stretched out his arm and gestured in mid-air.

"What time are you calculating? What data are you looking for? Why don't you just go and squat by the cafeteria entrance?"

Da Yong's logic carries the raw pragmatism of Northeast China.

"In this heavy snow, the roads are covered with ice. If she, a girl, slips and falls while walking on the road, you should be right next to her, rush over in one step, and catch her."

Dayong even demonstrated a horse stance for helping someone up.

"Isn't this a hundred times more effective than saying 'What a coincidence' at the stairwell? A hero saves the damsel in distress, physical contact, and the feelings just heat up instantly, right?" Chu Ge chuckled, his swivel chair creaking loudly.

"Dayong, what if that senior has a stable stance and doesn't slip? Lu Jia can't just go up and push her, can he?"

"It's fine as long as you didn't slip."

Da Yong said confidently.

"When you get to the cafeteria window, don't care what she's eating, whether it's spicy hot pot or congee. Just run up to her, swipe your meal card, get two of the most expensive braised pork and chicken legs, and force them onto her plate. Then say, 'Senior, it's cold, eat more meat to keep warm.'"

Da Yong patted Lu Jia on the shoulder.

"Women like practicality. If you cook braised pork for her, she'll remember you for life. If you secretly calculate the odds of her getting it, she'll think you're a pervert."

Lu Jia was shocked by Da Yong's hardcore theory about serving food.

The image of him forcibly shoving the braised pork into his senior's hand flashed through his mind, and he broke out in a cold sweat.

"Dayong, this is too reckless; it's not like me..."

Lu Jia waved his hands repeatedly.

"Hey, you intellectuals, you're just too cunning and too timid."

Da Yong sighed in exasperation.

Chen Zhuo leaned against the back of Chu Ge's chair.

He listened to Chu Ge's hacker talk and Da Yong's hardcore practice.

It's a bit frustrating; they're all single guys and they still have to get hit on by others.

"Lu Jia".

Lu Jia turned her head and looked at Chen Zhuo, as if she had grasped the last straw.

"Brother Zhuo, do you think there's a problem with my mathematical model?"

Chen Zhuo straightened up and walked to the whiteboard.

He pretended to carefully read through the normal distribution equation and transition probability matrix listed by Lu Jia.

"Well... from what I see so far, the formula should be fine. If you use this to apply for a research grant in consumer behavior at the business school, the professor will definitely approve it."

Chen Zhuo gave a very fair academic evaluation.

Lu Jia's expression softened slightly, and hope rekindled in her eyes.

"So that means if I follow this plan tomorrow, I have a 72% chance of success?"

Chen Zhuo turned around, looked at Lu Jia, a faint smile on his lips, and spoke in a serious tone.

"Yes, if it's in a vacuum environment."

Chen Zhuo reached out and took the whiteboard marker from Lu Jia's hand. Next to the parameter on the whiteboard that represented the sudden drop in temperature and snowfall today, he drew a big question mark. "But there's a problem."

"What's the problem?"

Lu Jia nervously adjusted her glasses.

Chu Ge and Da Yong also curiously came over.

Chen Zhuo tapped the question mark with the tip of his pen, his tone tinged with a smile.

"It's snowing the first snow of the day, the wind is strong, and the temperature is below -2 degrees Celsius."

Chen Zhuo looked into Lu Jia's eyes.

"In your Markov chain, have you added a status option like this, in case the senior sister thinks it's too cold outside today and doesn't want to go downstairs at all?" Lu Jia was stunned.

Chen Zhuo continued speaking in a gentle voice.

"What if she asked her roommate to bring back some fried rice? Or worse, what if she felt it was too cold to eat in the cafeteria and just set up a small table on her bed and made herself a bowl of Master Kong braised beef noodles?"

The dormitory fell silent instantly.

Lu Jia remained in the position of adjusting her glasses, as if she had been put on pause.

He stared wide-eyed at the dense, flawless formulas on the whiteboard.

A few seconds later, the light in his eyes went out completely.

A loud thud.

Chen Zhuo casually tossed the whiteboard marker into the whiteboard tray, the sound like the last straw that broke the camel's back.

Lu Jia's legs went weak, and she slumped into her chair.

"Instant noodles..."

Lu Jia stared blankly at the ceiling, muttering to himself.

"Yes... girls can stay home on snowy days..."

He spent several nights building a perfect model using all his knowledge of calculus and probability, only to have it instantly shattered by Chen Zhuo with a bowl of instant noodles.

"Pfft~ Hahaha!"

Chu Ge was the first to react. He bit into the lollipop in his mouth, pointed at Lu Jia who was slumped in the chair, and laughed so hard that the swivel chair almost tipped over.

"Haha, Professor Lu, your mathematical model was completely destroyed by a bowl of instant noodles!"

Wang Dayong also realized what was happening and chuckled to himself.

"I told you all that was pointless, Lu Jia. Listen to me, we'll ambush her at the cafeteria tomorrow, or just buy her braised pork."

Da Yong walked over and patted Lu Jia on the shoulder, almost making Lu Jia fall face down on the table.

Even in the stairwell, one could hear Chu Ge's unrestrained laughter and Lu Jia's heartbroken sigh.