The boy came back to his senses and rearranged his thoughts.

Since it is a case of disappearance, let's change the starting point and start with the disappearance.

He opened the news station and found that it was already densely covered with all kinds of missing news and help posts.

"Two high school students in the west of the city have been missing for three days, and the last time they appeared was in the game hall they went to after school.

"Zhao, a woman in the east of the city, went out for a night run two days ago and never returned home, and the police launched a search according to the common night running route provided by her boyfriend, but there was no trace."

"The 19-year-old girl disappeared after getting into a taxi at night, and the GPS signal of the taxi also mysteriously disappeared on the night of the crime, and further search is still ongoing."

"Xiao Han, a 14-year-old junior high school girl, was lost on her way home from school four days ago."

"The Qiantang City Police reminded that criminals have been rampant in the west and south of the city recently, so you should travel in a group at night and pay attention to safety."

He frowned and looked at them one by one, and suddenly smiled excitedly, quickly drawing a path map on the blank paper.

Resist the joy of impulse,First open the crawler software,Although the software icon is a little spider,But it's not so panicking.,It's just a cute gadget that grabs information along the vine.。

What the? Expired membership?

The boy was dissatisfied, and he had to pay more than 100 yuan a month in membership fees, and he couldn't let it go, but he only had a few hundred yuan of pocket money in his pocket, and he was saved and spelled out, and he always felt strange if he asked his mother for money to buy software.

Since you don't have the money, make one yourself. The boy gritted his teeth and nodded vigorously, stretching his fingers eager to try.

There are a lot of open source frameworks, and the shortcomings are in the configuration and debugging of the host, there are crawlers of various versions and languages, and redundancy is the biggest enemy, especially in Gu Wencheng's poor remote host, the bandwidth of the small water pipe is the same as the configuration of the little squirrel's heart.

He smiled bitterly, he was naturally unfamiliar with python that was more suitable for crawlers, he found the familiar PHP version on the open source website, the author was an Indian child, different host operating systems, and the commands for remote installation were different, but fortunately, the open source website supported remote cloning, and it was deployed in an instant.

Strange, but it didn't work? Sure enough, the system is wrong.,In order to use Torch to develop artificial intellectual disability, the boy has endured the pain and washed into Ubantu.,Now if you want to go back to php, you have to change back to CentOS?,The boy beat his chest.,Back up the poems that are called artificial intellectual disability by classmates one by one,Reinstall the host.。

20 minutes passed,The crawler is deployed,The boy tested a local news station,The path setting is more difficult,The page structure of different websites is different,Some of the headlines of the Class attribute are scribbled,The boy endured his anger while adjusting them one by one,Half an hour later,Three news stations have been crawled,In the last 7 days, as long as the news with the missing word has been arrested。

While the iron was hot, he added ten more local news stations and two local forums, two or three websites had a very strong anti-crawler mechanism, and they were banned in less than a minute, he shrugged his shoulders with a wry smile, anyway, there are already thousands of news coming in.

News Scrape, Achieved! The boy smiled with bright eyes, looked back at the sleeping girls behind him with joy, and clenched his fists again.

The next step is extraction, first of all, deduplication, which can be done with the distinct command. With more than 700 news and posts left after deduplication, the boy gasped.

In just a few days, there were more than 700 disappearances in the city!

The hardest part of the extraction job is the identification of places, the boy doesn't have a dictionary, it would be nice if he had the data of the logistics company - think about it for a moment, and the problem will be solved quickly.

He opened the map webpage of Wuji Company, found the API interface, and extracted all the street names, road names, restaurant names, bridge names, and river names in Qiantang City by way of web page extraction, after all, the workload was not large, so he didn't even let go of the public toilet. After importing the new data table, the self-made dictionary is completed.

With dictionaries and familiar commands, hundreds of thousands of words of news were reduced to 700 fragmentary place names in five minutes, and after being deduplicated again, only more than 500 place names remained.

Knowing that he had just extracted the coordinates by the way, the boy raised his casual eyebrows, took a sip of tea to stretch his body, leaned on the back of the chair and rested for a while to return to the screen, and re-called the API of Wuji.

Only then did he find out that Wuji had already provided the function of data maps, and it was free as a beta version, the boy smiled happily, he re-downloaded the data package of the place names, and after typing the command again, the corresponding GPS coordinates appeared behind more than 500 place names.

Two hours have passed since the beginning, and the boy smiled excitedly as he looked at the map densely marked with red dots on the screen, and it was amazing to see how much progress had been made in such a short period of time! This is a rate of advancement that has not been achieved in the past.

Looking at the screen, Gu Wencheng's mouth gradually opened with joy, and his face was full of horror.

The red dots are distributed in a total of multiple large circles, most of which are distributed in the south and west of the city, the closest circle to themselves, and the center of the circle is the intersection of two blocks south of their home, with a radius of about two kilometers, whether it is a school or their own home, they are covered!

The last is data fitting, no matter what, the data is in line with the power law distribution, the boy first deleted the data from other places, leaving only a circle in his own area, he removed the center of the noise, only the outermost point distribution remained, and the outline of a ring was put together, the circle fitting can use the least squares method, he has not used such a formula, Wen Cheng frowned.

He quickly searched for the principle of least squares, and it took more than ten minutes to quickly gnaw it through, and then came to the open source code website, but he couldn't find the php version, some of which were C language versions, and he was not very familiar with them, but the principles were the same, not to mention that they could be applied directly, and there was no need for secondary development at all.

He took a deep breath, downloaded MATLAB, and re-imported the data, with a crisp enter key, and the fitting was over!

Wen Cheng looked at a perfect circle on the screen and smiled with satisfaction, rubbed his eyes, and imported the data into the map again.

The center of the circle on the map is called Yuantuo Building,

Gu Wencheng suddenly remembered that it was an unfinished building.

After saving the results, he turned off the computer, resisting the urge to tell the sleeping girl the answer, Wen Cheng came to the door and quietly closed the door, and came to the sofa to lie down.

He looked at his phone, it was five o'clock in the morning, even if it was an hour, it was still enough to sleep.

The excitement seemed to be entangled in his brain like the dance of the little ghost, Gu Wencheng couldn't sink his mind no matter how hard he tried to close his eyes, he flipped through the phone randomly, and suddenly turned to a photo of a girl he had just taken a while ago, and he calmed down all of a sudden, he just watched quietly like that, his mood gradually stabilized, and sleepiness poured in.