After Lin Zhixia finished speaking, she pulled Jiang Yubai forward as they ran.
The castles and fortresses designated as bases for Groups A and B were both located at higher elevations, while most of the criss-crossing tunnels were positioned lower.
Under Nie Tianqing’s interference, the bubble balls rolled into different tunnels. Nie Tianqing moved swiftly through the tunnels, kicking balls around without any hesitation.
Lin Zhixia surveyed the entire situation and summarized, “If we view this game as a graph theory problem, each junction in the tunnels represents a vertex in the graph. We have thirty-seven vertices in total. This map is already imprinted in my mind. Some tunnels are transparent while others aren’t, which also involves partially observable Markov decision processes…”
“Lin Zhixia!” Jiang Yubai declared righteously, “You don’t need to explain it to me! I trust you!”
Lin Zhixia pulled him into a tunnel: “Is it because you don’t understand and don’t want to listen? Then you’ll just have to follow me and always obey my commands.”
For the sake of the entire team’s victory, Jiang Yubai forgave Lin Zhixia’s provocation.
They ran toward a tunnel junction and quickly collected seven balls.
While rushing around, Lin Zhixia encountered Dong Sunqi from their group. Dong Sunqi shouted, “Come with me, there’s a shortest path here! Taking the shortest path will get us back faster!”
“No!” Lin Zhixia objected, “Always choosing the shortest path isn’t necessarily the globally optimal solution!”
Dong Sunqi was shocked: “What the hell are you talking about!”
Lin Zhixia responded, “Think about the three sides of a triangle! Sides A and B are both shorter than side C, but their sum will exceed the length of C. Such a simple principle! Why don’t you understand it when applied to graph theory?”
Dong Sunqi trembled with realization: “That seems to make sense! You talk a lot, so I’ll listen to you!”
Thus, both Dong Sunqi and Jiang Yubai became Lin Zhixia’s followers.
Within just a few minutes, they collected twelve bubble balls. However, misfortune struck unexpectedly as three people from the enemy group rushed toward them.
Ding Yan ran wildly while shouting, “Gan Shuli, Nie Tianqing! Let’s go rob Jiang Yubai! They have so many balls! They’re so good at collecting! We don’t need to collect balls ourselves, we’ll just follow them and rob them!”
Jiang Yubai remained completely calm. He stood composedly in place, looking calmly at Lin Zhixia: “You have a plan.”
Lin Zhixia’s eyes shifted, and surprisingly she said: “I don’t have a plan, let’s run! Help, help! Run quickly!”
“What?” Jiang Yubai was thrown into confusion, hurriedly following Lin Zhixia as they fled for their lives.
Lin Zhixia laughed and jumped, her ponytail coming undone. She, Jiang Yubai, and Dong Sunqi took turns sliding down the slide and bouncing into the trampoline.
Lin Zhixia, carrying four balls, ran at the front, her figure flashing quickly before disappearing into the complex maze of tunnels.
Jiang Yubai and Dong Sunqi were completely bewildered, like French troops who had lost the Maginot Line during World War II. Even though they still retained mobile forces, they didn’t know how to continue fighting.
“Take the blue tunnel! Then the red tunnel!” Lin Zhixia’s voice came from above, “Quickly put the bubble balls into our group’s central area!”
Jiang Yubai immediately asked, “Where are you going?”
Lin Zhixia said, “I’m going to find people from their Group B.”
“No!” Jiang Yubai tried to stop her, “Lin Zhixia, don’t go!”
Lin Zhixia bid him farewell: “Once I leave, I don’t know if I’ll be able to come back!”
Jiang Yubai stepped onto the entrance of the blue tunnel: “Where are you? I’ll come rescue you!”
Lin Zhixia was determined to go: “No need, I can’t be a coward! You stay home and protect the bubble balls well, protect every bubble ball! That’s our last hope for victory!”
Dong Sunqi was also distressed: “Lin Zhixia, go quickly! We will always remember you!”
“What are you saying?” Jiang Yubai began criticizing Dong Sunqi, “We’re a team, how can we abandon our teammate? Don’t you have something you want to protect?”
Dong Sunqi answered firmly: “Yes! I want to protect the bubble balls! Lin Zhixia told us to protect the bubble balls, you should hurry to our Group A’s central area!”
The two of them rushed toward Group A’s base center.
*
In the suspended tunnel, Nie Tianqing suddenly said, “I hear footsteps. Lin Zhixia is coming.”
The three members of Nie Tianqing’s group didn’t run. They stood still, discussing their strategy.
Ding Yan revealed, “Lin Zhixia’s nickname in our class is ‘freak.’ She’s very smart, you should be careful.”
“She’s only nine years old,” Nie Tianqing said, “How smart can she be no matter what?”
Ding Yan’s expression changed slightly: “She can memorize text in just three seconds!”
Nie Tianqing didn’t believe it.
Ding Yan angrily said, “It’s true! I’m a dog if I’m lying!”
Gan Shuli also said, “It’s true, she’s very smart.”
“Don’t boost others’ confidence while diminishing your morale,” Nie Tianqing, educated them like an older brother, “The opponent isn’t that scary. There are three of us; if we play rock-paper-scissors against her, can’t we beat her? Each of us has a fifty percent chance of winning!”
“That makes sense!” The person responding was Lin Zhixia.
Following Nie Tianqing’s logic, Lin Zhixia said to them, “Fifty percent cubed equals 0.125; my probability of winning is only 0.125.”
Nie Tianqing asked, “Why is it 0.125?”
Lin Zhixia tilted her head: “I must beat each one of you. The probability of winning the first time is 0.5, the second time 0.25, the third time 0.125… Isn’t that what you said? You assumed the probability of winning in each one-on-one match is 0.5…”
Nie Tianqing frowned: “But, Lin Zhixia, if you play rock-paper-scissors with us, once you lose, you can’t continue. Why are you calculating probability using powers of 0.5?”
“Think about it this way,” Lin Zhixia explained patiently, “When I play with the three of you, there are four possible outcomes. The first outcome is that I lose in the first round, with a probability of 0.5. The second outcome is that I lose in the second round, with a probability of 0.25. The third outcome is that I lose in the third round, with a probability of 0.125. The fourth outcome is that I win in the third round, also with a probability of 0.125. The sum of these probability events equals exactly 1, check it yourself! The prerequisite for me to enter the second and third rounds is that I won the previous round. However, you should know that winning the previous round is not the final state.”
Nie Tianqing had a sudden realization, clenching his right hand into a fist and hitting his left palm: “I understand now.”
He turned to look at his two companions: “Isn’t that great! We have a 0.875 probability of winning!”
Ding Yan trembled slightly: “Nie Tianqing, after all she’s said, you still think you can win? She’s tricking you. I don’t believe it.”
Nie Tianqing ignored Ding Yan. He walked toward Lin Zhixia and said with fighting spirit: “Let’s begin, Lin Zhixia, rock-paper-scissors.”
Lin Zhixia happily agreed.
Then, they both made their moves simultaneously—Nie Tianqing showed rock, Lin Zhixia showed paper.
Nie Tianqing was shocked and froze in place.
Lin Zhixia clapped her hands together and jumped in front of Ding Yan.
Ding Yan was terrified inside. He reluctantly showed scissors, while Lin Zhixia showed rock. Ding Yan wore an “I knew it all along” expression and also began counting down the three minutes of freeze time.
Only Gan Shuli remained from Ding Yan’s group.
All the group’s hope rested on Gan Shuli.
Gan Shuli mumbled, “I… scissors rock…”
“Gan Shuli,” Lin Zhixia patted her shoulder, “don’t be nervous.”
The tunnel junction was an enclosed space. Glass windows were attached to both the left and right sides, with ventilation holes at the top. Gan Shuli looked outside and could see the trampoline, zip line, and chandelier. She steeled herself and faced Lin Zhixia directly: “Lin Zhixia! Rock-paper-scissors!”
After speaking, she opened her five fingers, forming “paper.”
Lin Zhixia’s move seemed to come before Gan Shuli’s. She had already made a scissors sign before Gan Shuli could react.
Gan Shuli was surprised: “You… won again.”
Lin Zhixia smiled and said, “Oh, it’s all luck.”
What Lin Zhixia was thinking was—it was all luck that made her naturally different from others. Through observing various details, she could predict each classmate’s behavior.
Gan Shuli applauded her: “Such good luck.”
“I told you so!” Ding Yan warned Nie Tianqing, “I knew it all along! We can’t beat her!”
Nie Tianqing brought up old accounts: “If you knew all along, why did you bring us to rob Lin Zhixia’s group?”
Ding Yan was left speechless. He just couldn’t stand seeing Jiang Yubai happily collecting balls with ease while following Lin Zhixia. In just a few minutes, they had collected a pile of balls! Why? Why didn’t Jiang Yubai have to think? He didn’t want to think either!
Pitiful were the three members of their group, all frozen in place.
Lin Zhixia had already run far away.
On her way back to the base, Lin Zhixia continued collecting balls. She was so happy that her long hair had come loose, falling on her shoulders like a little madwoman. But she didn’t care at all. She collected four balls, rushed into a tunnel, and bumped right into Jiang Yubai.
Lin Zhixia fell to the ground immediately.
Jiang Yubai knelt and helped her with both hands.
She sighed, “The four bubble balls all rolled away, go pick them up quickly…”
Jiang Yubai only asked her, “I’m sorry, did I hurt you? My family has a doctor.”
Lin Zhixia shook her head: “No.” Then she asked, “Why are you apologizing to me? I bumped into you too. You didn’t do it on purpose. Force acts in both directions.”
A red hair tie was hanging at the end of Lin Zhixia’s hair. Jiang Yubai gently removed her hair tie: “Tie your hair up. In the tunnel, your hair shouldn’t block your eyes; you must see the path.”
Lin Zhixia had already picked up three bubble balls. She sat on the ground with her back to Jiang Yubai: “Help me tie my hair! Quickly!”
Jiang Yubai was startled: “I… I don’t know how to tie hair.”
Lin Zhixia immediately threw the bubble balls into his arms and snatched the red hair tie from his hand. She tied up her long hair while muttering, “Tying hair is very simple.”
Jiang Yubai said, “I’ve never learned how.”
Lin Zhixia told him, “There are many things so simple that you don’t need to learn them, you can master them just by looking once.”
From a distance, Dong Sunqi let out an earth-shattering roar: “Jiang Yubai! Lin Zhixia! Where are you!”
“Let’s go!” Lin Zhixia pulled Jiang Yubai up, “Let’s continue collecting balls!”
Jiang Yubai asked her, “Are you still using the shortest path algorithm?”
Lin Zhixia looked back at him once, leading him forward as they ran: “Of course! I have a Floyd algorithm matrix in my brain! All tunnel junctions are vertices of the graph. When the matrix doesn’t work, I build a Dijkstra tree, which also grows in my brain. It’s just a fusion of greedy, exhaustive, and pruning algorithms, as simple as tying hair—no need to think, you’ll get it just by looking once! I’ll take you on the fastest route! Let’s go home together!”
Jiang Yubai couldn’t help but admire her. Hearing her say, “I’ll take you on the fastest route, let’s go home together,” Jiang Yubai was very happy—this time their Group A would win!
The path in the tunnel was rugged. Jiang Yubai and Lin Zhixia each carried four balls. Jiang Yubai observed the enemy’s movements and wondered, “They’re not chasing us anymore.”
Lin Zhixia laughed heartily: “They’ll soon go to our Group A’s base center to rob Dong Sunqi. We need to run back to Group A’s base central area as quickly as possible before they launch their sneak attack!”
“What!” Jiang Yubai accused, “They’re so treacherous!”
Lin Zhixia comforted him: “Don’t worry! I’ll protect you!”
She jumped onto a pipe.
Jiang Yubai placed all four balls from his arms into the pipe. Then, he gripped a ring with one hand, standing on the zip line track, and turned his head to Lin Zhixia: “You go back to the base first! I see two balls on the trampoline!”
Lin Zhixia instructed him: “Be careful, go and come back quickly!”
Jiang Yubai flew toward the ground like the wind. He leaped and landed on the trampoline with very stable footing. His landing posture was also very skillful, using an on-the-spot roll to reduce the impact—the trampoline didn’t even bounce up and down.
He picked up the precious bubble balls and looked up at Lin Zhixia in the castle.
Lin Zhixia stood by the castle window, extending one hand and waving to him.
Jiang Yubai recalled the fairy tales he had read—princesses always stood in castles, waiting for princes to slay all the demons, waiting for princes to rescue them.
But the princess before his eyes was different.
The princess before his eyes was more like a prince who cut through thorns and brambles.
The stories in fairy tale books were wrong. From what he had witnessed, princesses could also be unstoppable and ride the wind and waves.