Wang Xueba System

"The three contestants, please stop what you're doing." Zhang Yuqing said, looking at Hu Bin with a smile.

Hu Bin put down his hands in frustration, and turned to look at the big screen.

Immediately afterwards, a look of shock slowly bloomed on Hu Bin's face.

"Unexpectedly, I am the only one who didn't finish it?" Hu Bin's eyes were a little frustrated, and even more shocking, "There is another person who finished it in 3 minutes and 20 seconds?"

"How could it be so fast? Is the gap so big?" Hu Bin looked at Luo Hao.

"Okay, after 10 minutes of competition, the result is now out." Zhang Yuqing said with a smile, "Congratulations, Luo Hao and Zhang Yi, who have successfully completed this question, and both of them have obtained the qualification for the second question !"

"Hu Bin, it's a pity that you didn't complete the requirements of the question this time, so you can't proceed to the next test, so you can't score this question." Zhang Yuqing looked at Hu Bin, with a restrained smile on his face, and said, "But , there are two more questions in the back, come on!"

"About this color flip game, I don't know if this is the first time you have seen it. Anyway, I have never played it before." Zhang Yuqing looked at the audience in the audience and said with a smile, "When I first read the question, I felt that this question It shouldn’t be difficult, and it should come out after a few more clicks. But then I found out that because the color of the row and column of the clicked grid will flip, it is still very disturbing.”

"However, if there is no time limit, many people should be able to do it, but it is really difficult to complete the game within 10 minutes when I first saw this game."

Having said that, Zhang Yuqing looked at Zhang Yi: "I don't know what method Zhang Yi used to complete this problem?"

"This..." Zhang Yi scratched his head suddenly, a little embarrassed, "I didn't think of any good way, take one step at a time, and when choosing each step, look at which one is more cost-effective in the current state. , I didn’t expect it to be completed.”

"It seems that our classmate Zhang Yi is very lucky." Zhang Yuqing smiled, and then looked at Luo Hao, "Then I wonder if our classmate Luo Hao has any good ideas? Or is it that student Luo Hao is luckier than Zhang Yi?" Is student Yi better?"

"This game looks a little difficult, but in fact, if you figure it out, you will find that it is actually very simple, but you need to change your thinking." Luo Hao hesitated and said, "At the beginning, I was also fooled by this topic. For a moment. I only realized it later.”

Although he felt that saying this might offend people, he still told the truth.

"According to the rules of the game, clicking on a square will cause the color of the row and column to change, and each square has only two positive and negative situations. That is to say, as long as each square is flipped an odd number of times, we can reach our goal. Purpose. If flipped an even number of times, it is the same effect as no flip."

"So, after I clicked a few times, I found something that made me happy. This is exactly 5x5 squares, and the rows and columns are odd numbers. That is to say, the easiest way is to randomly find one of the rows or One column, click on the squares on this line in turn, and you will be able to meet the requirements of the topic."

After Luo Hao finished speaking, he didn't forget to complain: "There is no restore button on our answer board, so after I discovered the pattern, I couldn't restore it directly, so I could only click back in order according to the appearance in memory. "

"Uh..." Zhang Yuqing was stunned for a moment, "I didn't expect this question to be so simple after classmate Luo Hao's explanation."

"That's true." Zhang Yi also said, "It's a trap for inertial thinking."

"This..." Hu Bin was a little frustrated.

"Okay, next, there is one more question about the unconventional question this time, and this question can be solved successfully, and the two of you can get 25 points for this question. If the second question is wrong, no points will be awarded. "Zhang Yuqing looked at Luo Hao and the two of them and said.

"understood."

Luo Hao and Zhang Yi looked at each other and nodded.

"Second question, please read the question." Zhang Yuqing started to read the question after a reminder, "As shown in the picture, there are 5x5 lights, and the current status is different. There are lights on and lights off. However, due to circuit reasons , when a certain light is turned on and off, the 4 lights up, down, left, and right of this light will also change state. If it is in the off state, it will change to the on state, and vice versa."

"Two contestants, please light up all the lights within the least number of times. Compared with the two contestants, the person with the fewest number of operations wins and gets 25 points. If the number of operations is the same, the one with the shortest time If the player wins, they will get 25 points. If they fail to complete within 10 minutes, neither side will score.”

"Please answer!"

With Zhang Yuqing's order, the same situation as before appeared on the big screen, but this time there was no projection of Hu Bin's answer board.

"The rules have changed this time." Luo Hao murmured in his heart, "But there should be some trick, right?"

At this time, Zhang Yi on the other side was also thinking, and did not rush to act.

Ten seconds later, Luo Hao started his operation.

For a moment, in the projection of Luo Hao's answering board on the big screen, each light bulb kept changing between on and off.

After Luo Hao started, Zhang Yi also started his operation.

For a while, the stage fell silent.

After 2 minutes, Luo Hao stopped his operations.

At this time, on the big screen, in the projection belonging to Luo Hao's answering board, all the lights have been lit.

in front of the TV.

"Luo Hao, how did you come up with the idea so quickly?" Huang Xi asked, "I wanted to ask you before, but I forgot later."

When Luo's mother heard the words, she also looked at Luo Hao.

"Although this rule is not the same as the previous one, it is still the same." Luo Hao explained, "It's the same, a lamp that has been changed twice is equivalent to no change, and the only one that can affect the brightness of this lamp is this one. These 4 lamps are located in the upper, lower, left, and right positions of the lamp."

"Then, the easiest way is to use the lights in the next row to turn on all the lights in the previous row until the lights in the penultimate row are all on. The last row requires multiple operations, but because there are only 5 lights in the last row Light, so there are not too many possible situations. Considering the symmetry of the square, there are only a few situations that need to be considered.”

"As long as this is solved, then we can achieve our goal." Luo Hao said with a smile, "However, this is only the result of achieving all lights, but it is not necessarily the least number of operations."