The number held by Liang Jingmo is "3".

In other words, one of the "1A1B" that Xiang Nanxing tried to come up with just now belonged to Liang Jingmo, and the other was held by one of the opponents. Coupled with the "7" held by Xiang Nanxing, three of the four password digits have been delineated in the range of these five digits, and what needs to be done now is to narrow down the range and find the last number.

The "5638" entered by Liang Jingmo at this time is exactly in accordance with this line of thought.

He divided the remaining five numbers into two groups, "568" and "09", and first determined which group the remaining numbers were in. Then, assuming that your "3" is the "A" in the first test, you put it in the same position as the last time. The best case is "2A", followed by "1A", both of which indicate that the third digit of the password is "3", and the range of the last digit can also be determined, so just try slowly and adjust the distribution on the other three positions.

The worse result is "1A1B", which is equivalent to saying that the last digit is in "568", but it is still impossible to completely determine whether "3" is the "A" or "B", and the follow-up work needs to consider different possibilities. But even if it's complicated, Liang Jingmo basically sorted out the various changes here just now, and it can be regarded as something that can be dealt with.

"The final result was '1B'...... Well, if you compare it to a lottery, this should be considered a 'last auspicious'. Liang Jingmo glanced at the feedback results on the screen and muttered to himself.

The results of "1B" don't convey much information, but they are unmistakable. First of all, this result shows that the last password number is either "0" or "9", and the goal of narrowing the range is achieved. Secondly, Liang Jingmo also knew that the "3" was not in the right position, so he could consider it in other positions.

"In this case, as long as you determine the correct position of '3', you can remove the wrong answer from '1', '2', and '4'." Xiang Nanxing leaned over and saw the entered test numbers from Liang Jingmo's fingers, and after a little thought, he understood his companion's intentions, "But your intention for this test is too straightforward, right?" If you were to be seen secretly, wouldn't you be able to see what you were trying to do at a glance? ”

"Stupid, that's why I'm holding it so hard."

Liang Jingmo looked left and right, his cautious expression was like a miser worried about the treasure under his bed, looking nervous, but a little funny. However, Xiang Nanxing knew that at least nine points or more in his posture were acting skills, and only one point was the original caution. After all, his hands blocked the key positions on the screen, and he also used his body to block the surrounding vision when typing, even if the host was really peeping from a distance somewhere, it was impossible to see the input numbers and the feedback results on it. The reason why he put on such a small family appearance is just to pretend to be weak in front of the two unfamiliar hosts, so that people mistakenly think that "this guy is just like this".

This also echoed Xiang Nanxing's plan just now. If "Lynx" Kara really fell for the trick and believed Xiang Nanxing's fictional situation, then when he saw the current cowering Liang Jingmo, it would be easier for him to believe that this was a person who would make low-level mistakes when typing.

"But it's not necessary to keep blocking like this, I can see it clearly anyway." He moved away slightly, relinquishing the center of the screen, "Hey, it's your turn, you can type 'a second time'." ”

Xiang Nanxing smiled: "Don't you give some instructions?" ”

"Think for yourself." Liang Jingmo raised his eyebrows, "Don't you want me to teach this kind of thing?" ”

Xiang Nanxing shrugged and stood in front of the touchscreen. The "second time" in Liang Jingmo's mouth naturally refers to Xiang Nanxing's test opportunity this time. As Xiang Nanxing had previously envisioned, the biggest advantage of the two of them acting together was that they could use the content of the second person's input to cover up the test results of the previous one. Numbers like the ones Liang Jingmo just entered, if they leave them alone, the opponent will immediately guess that Liang Jingmo is holding a "3" as soon as they see what is on the screen. At this time, Xiang Nanxing needs to enter another set of numbers immediately after him to replace the displayed content.

But even if it's just a cover-up, there's a lot of attention to what you type. Some people may choose four numbers that have nothing to do with the password and make the result "0B", which at first glance does not seem to leave any clue for the opponent, but in fact, it is the opposite of helping the opponent eliminate the four wrong answers. Considering that the opponent already has two correct numbers, this "0B" message alone will help them narrow down the range of the two cipher numbers to less than four digits.

Of course, Xiang Nanxing can also choose three wrong numbers and mix his own numbers in them. If you're lucky enough to have an A's, you'll be able to know where your numbers are, but most of the time you'll end up with a "1B" – a headache for your opponents, but a waste of a valuable test opportunity for yourself.

All things considered, the best result of this test should be "2B", and the two numbers hit are from the opponent's side. As a result, the adversaries only know that their two numbers are in the password - which is nonsense at all - but they cannot determine their location, and only rule out the two wrong numbers. Xiang Nanxing, on the other hand, can confirm the opponent's numbers from this and master all four numbers at once.

Slightly worse than this result is "1B" and "1A1B", with the worst being "1A" or "2A", where the former will help the opponent eliminate three wrong numbers or roughly determine the position of their own number, while the latter will make the opponent confirm the position completely. But no matter what the case is, they can help Xiang Nanxing and them get some information while hiding their numbers.

"But then again, in order to be so perfect, you have to know almost what the correct password is if you use the wrong number to make up the number." Xiang Nanxing pondered, "With these clues at hand now...... Not. ”

He thought and counted as he typed four numbers into the touchscreen. After that, his finger hovered over the "confirm" button, and his mind raced to test his choice. The more things he listed, the more he fell into chaos.

"Don't think about it, the more you think about it, the more chaotic it becomes. That's a good answer. Liang Jingmo nodded, "No, let's be honest, judging from the information we have so far, the best answer is this." Speaking of which, I really want to compliment you. ”

The number entered by Xiang Nanxing is "0168". This is a combination of two "suspected" numbers and two distractors. The former refers to the two numbers "0" and "1", Liang Jingmo's test just now has narrowed the range of one of the numbers to between "0" and "9", and the other number will appear in the middle of "1", "2" and "4", that is to say, the probability of Xiang Nanxing's input of these two numbers hitting the answer is one-in-one and one-third respectively, and there is a one-sixth chance to achieve the optimal "2B" result, and Xiang Nanxing cleverly used the results of Liang Jingmo's test just now to "0168" The probability of "A" is minimized.

"It's a very interesting transposition." Liang Jingmo praised, "Since the result of '1A1B' appeared in the first round, and it was confirmed that '3' is not in the third position, then if the correct number is '1', its correct position should be 'first', and if you put it in the second position, even if the number is correct, it will only give back a 'B', and they can't be sure that it changed from 'A' to 'B' because of the shift." ”

"As for the '0' in the first place...... If '1' is the correct number, then it occupies the position of '1' and is destined not to get the feedback of 'A', only when the other number is '2' or '4', and '0' happens to be the correct number, it has a one-third chance of falling into its own position, resulting in an 'A'. If this happens, they can determine its location, but if such a small probability thing does happen, then it is better to give it to them. ”

He clapped his hands and applauded: "Overall, well done." ”

"I always feel that you have something in your words, and it doesn't sound very comfortable." Xiang Nanxing replied with a wry smile. He thought about it, sorted out his thoughts one last time, and then pressed the "confirm" button. This time, he didn't have to block the screen like Liang Jingmo, after all, after this input, neither of them could modify the content on the display, and sooner or later they would be seen by the other party.

And judging by the results...... His attempt was not bad.

"The result is '1B', which is okay." Liang Jingmo nodded.

There are two possible outcomes, either the first digit is '1' and the other is '9', or one of the cipher digits is '0' and not in the first place, and then one of the numbers in the second or fourth digit will be '2' or '4'. ”

He stared at the screen, quickly imagining a plan for the next round of testing in his head. As long as he continues to use the method of continuous input by two people, he will be able to let go of his hands and feet in the first input. In fact, he was one step away from the correct answer.

For example, next time he can type "3270" and test the position of "3", the correctness of "2", the position of "7", and the correctness of "0" and its position.

If only two of the four numbers are correct, it means that the correct number is "1379", and "1" locks the first place. On this basis, if "1A1B" is fed back, it means that "7" is the third place, "3" is the second or fourth, and "9" is also the second or fourth; If you give feedback "2B", it means that "9" is the third position, and "3" and "7" are the second or fourth respectively. Either way, just pick an indeterminate number and test its location to get the full password.

If there are three numbers correct, it means that the correct number is "0347", and "4" is determined to be in the fourth place. If the result is "2A1B", it means that "3" and "7" are in the correct position, and the correct password can be obtained by moving "0" from the fourth to the second digit; If it is "1A2B", then it is possible that "3" is the first, "7" is the second, and "0" is the third; Or "3" is the second place, "0" is the first place, and "7" is the third, just confirm the position of the "3" in the next test to draw conclusions; If it is "3B", it means that "3" must be the second digit, and "7" can only be ranked in the first place, and the remaining "0" is the third digit, plus the "4" in the fourth digit is the correct password.

If all four numbers are correct, the best result is, of course, a straight "4A", at least the second digit can be determined to be "2". If the feedback is "1A3B", it means that "3" can only be the fourth place, "7" will fall in the first place, and the remaining "0" will be the third place, resulting in the answer "7230". If you get "2A2B", it means that one of the "3" and "7" must be "A", and the other can be reversed with "0" to get the correct password, so that as long as you test the position of any number in the next input, you can guess the correct password from the result.

"The conclusion is that it is going well." "Regardless of the outcome, my side can draw conclusions from the 'second input' without revealing the information," Liang said. Of course, the premise here is ......"

They were discussing when they suddenly heard an artificial voice announcement coming from the radio on the floor.

"Attention everyone, there are players who have changed their numbers."

"So fast!"

He exclaimed, looked up in shock, and looked at Xiang Nanxing, who was also shocked.

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