The next day, Yu Wenbo didn't show anything unusual when he was in class, he was still the same, he liked to hide everything in his heart, I don't know why, I always felt a little chill down my spine, there were more people playing with mobile phones in class this morning, sure enough, the winter camp is also called the hibernation camp, many students began to drop the line, I looked at Xu Chao and was still taking notes seriously, and I didn't get distracted and continued to listen. I have been slowly disconnected since the afternoon, I have to say that there are people outside the world, there are days outside the sky, I used to feel that I was awesome, but now it seems that there is still a gap between myself and the real champion.

I took the time to send a message to Hengzi, I told her that I was also in Beijing, attending the winter camp, and Hengzi replied to me after a long time, she said, "I have a new boyfriend!" ”

"yes, is he good to you?"

"Not bad."

"Let's get together when we have time, and wait until I'm done with the winter camp."

"Okay."

I don't know why, when I heard that Hengzi had a new boyfriend, my heart was sour, and I still thought about Hengzi in my heart. Lao Huang and Lao Li also came to see me once, and told me that I must work hard alone, and I must go to the next level within seven days, and the two of them have been helping Zhou Tao consolidate the things of informatics now. Speaking of Zhou Tao, I am also on fire.

In the evening, when the campers were discussing, I saw Xu Chao and Zhou Tao sitting together, I didn't know what they were discussing, I walked up to take a look, it turned out to be a space flight plan topic, the topic roughly means that there are n experiments to do, and the corresponding money will be rewarded for doing it, but each experiment needs the corresponding instrument, and each instrument needs the corresponding money to start, and the arrangement makes the most money.

I saw that Zhou Tao was still telling Xu Chao about the concept of closed diagrams, and I couldn't help but laugh, he must have thought that Xu Chao was a half-ass, but I didn't know, Xu Chao's current programming ability was a little overwhelmed, Xu Chao saw me snickering on the side, so he said: "Mo Cheng, do you know how to solve this problem?" ”

"Okay, I know a little bit about it."

"Then tell me about it." Zhou Tao said disdainfully.

"Obviously, this is a dichotomous diagram, where each experiment is connected to the desired instrument, and the point weight of the experiment is positive, and the point weight of the instrument is negative, requiring the maximum weight to close the diagram. This is a question of whether to choose or not to choose, so it can be transformed into a model of least cut, and the selected ones are classified as the S set, and the ones that are not selected are classified as the T set. However, it is required that the profit is the largest, and the minimum cut is the smallest, so we have to change the angle and ask for the least amount of money, because all the experiments add up to a certain amount. In the minimum cut, if S is connected to the point represented by all experiments with a capacity as the reward money (class A arc), and all instruments to T are connected with a capacity as the money for the starting instrument (class b arc), if the class A arc is cut, then the corresponding experiment is classified as the T set, that is, if it is not done, then there will be a loss. If the class B arc is cut off, then the corresponding instrument is classified into the S set, that is, there is a loss. All the minimum cuts are the ones that make the least loss......"

"The general solution of the maximum weight closed graph: S to the point with positive weight, the capacity is its weight, the point with the negative weight is to the edge with T, the capacity is its absolute value, and then the edge capacity in the original graph is inf, ans = the sum of all positive weights - the least cut."

“bingo！” I gave Xu Chao a thumbs up.

Zhou Tao saw that the two of us sang and harmonized, and he felt bored and sat at another table, I moved to Xu Chao's side, Xu Chao said to me: "This person in your school is quite interesting, it seems that he doesn't even know some basic things, and he still comes to me to show off." ”

"Ahem, eighty percent of this person is a winter camp that relies on relationships."

"So he's misappropriating your spot?"

"Maybe?"

Xu Chao smiled and then continued: "How can we Young Master Mo have Yaxing today, come with me to discuss the topic." ”

I blushed and said, "Hu Xuecheng went with the people from his school today. ”

"Nonsense, I just saw the two of you walk in together."

I secretly rejoiced in my heart, and then said: "It's over in a few days, let's go and see the national flag raising together, I haven't been there yet." ”

"Okay."

Five days later......

Today is the last day of the winter camp, and Xu Chao and I got up early in the morning to go to see the national flag raising. Speaking of yesterday's exam, it was thrilling, Yu Wenbo was disqualified and banned for three years, I dare to conclude that it must be Yu Wenbo who started hacking into other people's computers, but this time it was not as simple as he thought.

Yesterday's finale topic is the problem of warehouse handling, in fact, this topic is difficult to say, simple and simple, the variable given by the topic is that the number of goods in the warehouse is unequal, there are n circular transportation lines around this warehouse, and the handling can only be carried in the adjacent two warehouses, how to carry the minimum amount of handling.

I've been thinking about this topic for a long time and have no idea, but I feel that it is the continuous shortest circuit practice of the smallest cost and the largest stream, but when the function is written, there are many errors, and the debugging has not succeeded for a long time, I calculated, and the data disappeared again, I raised my head and looked around, not only me, but the data of many students here disappeared inexplicably, and then they began to suspect that the school computer had a virus, but the computer used a different operating system, and there were a few new computers, and it was almost impossible to have a virus, The only possibility is that someone is using the LAN to do a trick.