Chapter 90: Shortest Path (5)

90 – Shortest Path (5)

A vast web of shadowy figures interwove into a crisscrossing giant net. By the time Lin Xun approached the glass door, at least eight of them had already closed in around him. Lin Xun’s ears were filled with the howling wind and the sharp sound of weapons cutting through the air—the claws of the demonic creatures possessed a hardness and sharpness that defied biological laws.

Sword Qi crisscrossed, radiating outward in all directions from Lin Xun, holding them off for a moment.

But holding them off for a moment was not holding them off forever. The consumption of Sword Qi was limited, directly tied to Lin Xun’s physical condition.

He had no intention of holding them off forever. The tip of his longsword struck straight at the glass door, and a tremendous recoil force shot through his arm, numbing his wrist and nearly causing the hilt to slip from his grasp. The blast-proof glass door was indeed sturdy—even with a strike at his Golden Core realm, it only produced a spiderweb-like crack. He struck it several more times, finally feeling a slight depression in the glass beneath his hand. Meanwhile, the short white figure inside the door was slowly walking toward him.

But by then, his wrist had already weakened and trembled from exhaustion, flushed with an unnatural redness.

Looking at the white figure, Lin Xun thought to himself that he had the skill to sever connections. No matter what level of demonic creature this girl was, he wouldn’t meet his end here. With this thought, he steeled himself and kicked at the tempered blast-proof door, already covered in dense spiderweb cracks!

With a crash, shattered glass rained down. Lin Xun also felt an indescribable pain in his knee joint, almost like a dislocation, but he could still walk.

The face of the white figure inside became clearly visible—a white dress, two braids on either side, familiar features. Without a doubt, it was the girl he had encountered in the psychiatric hospital, Lin Kexin. But unlike before, her eyes were completely covered in black, with no whites visible. She walked out from the depths of the dark subway tunnel like a lifeless puppet doll, eerie and ghostly.

Clearly, she was being controlled by a demonic creature. When Lin Xun had left the children’s hospital, she had still seemed like a normal girl—who was inside her body now? That “invisible friend”? If so, was this invisible friend the mastermind behind this trap? After Lin Kexin mentioned Subway Line 4, they had been misled into the basement of the small building. Or perhaps Lin Kexin and her friend had been in cahoots all along, jointly setting up this trap.

The purpose of this trap was undoubtedly to wipe out the entire cultivation world, with Lin Xun caught up in it as well—or perhaps… it was specifically for Lin Xun.

Lin Xun’s mind never stopped racing, nor did the Sword Qi around him. He knew that if a fight broke out, he couldn’t let himself be forced onto the subway tracks. With his Mortal Body, facing a steel monster like a subway train was even worse than facing the thousands of demonic creatures outside. So, Lin Xun fought while retreating, stepping back more than a dozen paces.

Lin Kexin also slowly emerged from the broken opening of the subway tunnel. She stared directly at Lin Xun, and the surrounding demonic creatures gradually ceased their movements.

Lin Xun stared back at her.

He spoke, asking, “What do you want?”

Lin Kexin continued to stare blankly at him, then tilted her head slightly, as if pondering something.

Then, in the next moment, her body levitated into the air and lunged toward Lin Xun in a bizarre posture! She extended her right hand, her slender fingers curling into a claw-like shape, aiming straight for the crown of Lin Xun’s head!

Even though they were still several meters away, the familiar sharp pain once again pierced his mind, just like the day the system had been damaged. He immediately knew that the demons would not negotiate with him, let alone make peace. Their goal was either to obtain something from him or to kill him.

At the same time, the other demons around him lunged forward, their dark shadows blotting out the sky. For a single person to face thousands of enemies was unimaginable from any perspective.

His power was limited. True, if he wished, he could unleash any number of sword Qi strikes, or strikes of any intensity, but he could not do both simultaneously. To increase the number of sword Qi strikes, he would inevitably sacrifice their strength. These demons were not only physically robust but also vast in number—especially with Lin Kexin, whose strength remained unknown.

This was no longer a case of a mantis trying to stop a chariot; it was more like a small twig floating on the water, attempting to block the impending flood of the Yellow River rushing downstream.

But Lin Xun did not panic.

The light flowing in his sword shifted, transforming back into the form of a keyboard.

In those two or three seconds of life and death, he called up a program and, with the speed of a programmer, tapped with five fingers to modify two parameters.

Some problems were unimaginable for humans, but not for computers. In an abstract sense, all concepts were mathematics.

Each demon had a position, abstracted as a point in three-dimensional space.

The sword in Lin Xun’s hand was also a point.

Between two points, a line could be drawn—the path along which demons or sword Qi moved, a mathematical concept: a road.

Thus, the entire scene became a graph.

In applied mathematics, there was a field called graph theory, and a class of problems known as combinatorial optimization. The layout of urban sewer systems, the planning of transportation routes, cash flow in financial networks—all were its domains.

How could Lin Xun block all the demons threatening his life in the shortest time possible and confront Lin Kexin head-on?

And while attacking the demons, how could he ensure the strength of his sword Qi was maximized within his capabilities?

The first problem was called the shortest path problem.

The second problem was called the maximum flow problem.

There were many established algorithms to solve these problems: Dijkstra, Prim, SAP, HLPP…

—This was mathematics, and the application of mathematics.

Amid the howling wind and the moment of life and death, Lin Xun’s expression remained unchanged as he pressed the run key.

Sometimes, facing demons was like facing a final exam. His heartbeat was steady because he was not someone who neglected his studies.