Một câu hỏi phỏng vấn của Google?
23 tên tù nhân được giam trong 23 phòng giam riêng biệt ở một nhà tù. Họ không có cách nào để trao đổi với nhau khi bị nhốt tại phòng giam của mình.
Nhà tù còn có một phòng khác, ở đó có hai công tắc gắn trên tường (A và B). Công tắc có phần tắt và bật nhưng ban đầu, chúng không rõ đang tắt hay bật.
Quản tù sẽ dẫn từng tù nhân vào phòng này. Tù nhân phải chọn tắt hoặc bật một trong hai công tắc.
Ở bất kỳ thời điểm nào, một người trong số 23 tù nhân có thể hô lên "tất cả tù nhân đã ghé qua căn phòng này". Nếu đúng, 23 tù nhân được thả. Nếu sai, họ bị xử tử.
Trước khi trò chơi bắt đầu, quản tù cho phép 23 người gặp và bàn bạc, lên chiến lược.
Theo bạn, họ có thể áp dụng chiến lược nào để được thả ra?
khoa học
,kỹ năng mềm
,công nghệ thông tin
,hướng nghiệp
,xã hội
Câu hỏi trên của bạn đã được dịch lại nên bài dịch này không rõ ràng làm cho người đọc cảm thấy thiếu dữ kiện để mà trả lời, sau đây là câu hỏi gốc:
The warden meets with 23 new prisoners when they arrive. He tells them, "You may meet today and plan a strategy. But after today, you will be in isolated cells and will have no communication with one another.
"In the prison is a switch room, which contains two light switches labeled 1 and 2, each of which can be in either up or the down position. I am not telling you their present positions. The switches are not connected to anything.
"After today, from time to time whenever I feel so inclined, I will select one prisoner at random and escort him to the switch room. This prisoner will select one of the two switches and reverse its position. He must flip one switch when he visits the switch room, and may only flip one of the switches. Then he'll be led back to his cell.
"No one else will be allowed to alter the switches until I lead the next prisoner into the switch room. I'm going to choose prisoners at random. I may choose the same guy three times in a row, or I may jump around and come back. I will not touch the switches, if I wanted you dead you would already be dead.
"Given enough time, everyone will eventually visit the switch room the same number of times as everyone else. At any time, anyone may declare to me, 'We have all visited the switch room.'
"If it is true, then you will all be set free. If it is false, and somebody has not yet visited the switch room, you will all die horribly. You will be carefully monitored, and any attempt to break any of these rules will result in instant death to all of you"
What is the strategy they come up with so that they can be free?
Đáp án: Hey, suy nghĩ đi rồi hãy xem đáp án :))
The team nominates a leader. The group agrees upon the following rules:
The leader is the only person who will announce that everyone has visited the switch room. All the prisoners (except for the leader) will flip the first switch up at their very first opportunity, and again on the second opportunity. If the first switch is already up, or they have already flipped the first switch up two times, they will then flip the second switch. Only the leader may flip the first switch down, if the first switch is already down, then the leader will flip the second switch. The leader remembers how many times he has flipped the first switch down. Once the leader has flipped the first switch down 44 times, he announces that all have visited the room.
It does not matter how many times a prisoner has visited the room, in which order the prisoners were sent or even if the first switch was initially up. Once the leader has flipped the switch down 44 times then the leader knows everyone has visited the room. If the switch was initially down, then all 22 prisoners will flip the switch up twice. If the switch was initially up, then there will be one prisoner who only flips the switch up once and the rest will flip it up twice.
The prisoners can not be certain that all have visited the room after the leader flips the switch down 23 times, as the first 12 prisoners plus the leader might be taken to the room 24 times before anyone else is allowed into the room. Because the initial state of the switch might be up, the prisoners must flip the first switch up twice. If they decide to flip it up only once, the leader will not know if he should count to 22 or 23.
In the example of three prisoners, the leader must flip the first switch down three times to be sure all prisoners have visited the room, twice for the two other prisoners and once more in case the switch was initially up.
Qthinh
Câu hỏi trên của bạn đã được dịch lại nên bài dịch này không rõ ràng làm cho người đọc cảm thấy thiếu dữ kiện để mà trả lời, sau đây là câu hỏi gốc:
The warden meets with 23 new prisoners when they arrive. He tells them, "You may meet today and plan a strategy. But after today, you will be in isolated cells and will have no communication with one another.
"In the prison is a switch room, which contains two light switches labeled 1 and 2, each of which can be in either up or the down position. I am not telling you their present positions. The switches are not connected to anything.
"After today, from time to time whenever I feel so inclined, I will select one prisoner at random and escort him to the switch room. This prisoner will select one of the two switches and reverse its position. He must flip one switch when he visits the switch room, and may only flip one of the switches. Then he'll be led back to his cell.
"No one else will be allowed to alter the switches until I lead the next prisoner into the switch room. I'm going to choose prisoners at random. I may choose the same guy three times in a row, or I may jump around and come back. I will not touch the switches, if I wanted you dead you would already be dead.
"Given enough time, everyone will eventually visit the switch room the same number of times as everyone else. At any time, anyone may declare to me, 'We have all visited the switch room.'
"If it is true, then you will all be set free. If it is false, and somebody has not yet visited the switch room, you will all die horribly. You will be carefully monitored, and any attempt to break any of these rules will result in instant death to all of you"
What is the strategy they come up with so that they can be free?
Đáp án: Hey, suy nghĩ đi rồi hãy xem đáp án :))
The team nominates a leader. The group agrees upon the following rules:
The leader is the only person who will announce that everyone has visited the switch room. All the prisoners (except for the leader) will flip the first switch up at their very first opportunity, and again on the second opportunity. If the first switch is already up, or they have already flipped the first switch up two times, they will then flip the second switch. Only the leader may flip the first switch down, if the first switch is already down, then the leader will flip the second switch. The leader remembers how many times he has flipped the first switch down. Once the leader has flipped the first switch down 44 times, he announces that all have visited the room.
It does not matter how many times a prisoner has visited the room, in which order the prisoners were sent or even if the first switch was initially up. Once the leader has flipped the switch down 44 times then the leader knows everyone has visited the room. If the switch was initially down, then all 22 prisoners will flip the switch up twice. If the switch was initially up, then there will be one prisoner who only flips the switch up once and the rest will flip it up twice.
The prisoners can not be certain that all have visited the room after the leader flips the switch down 23 times, as the first 12 prisoners plus the leader might be taken to the room 24 times before anyone else is allowed into the room. Because the initial state of the switch might be up, the prisoners must flip the first switch up twice. If they decide to flip it up only once, the leader will not know if he should count to 22 or 23.
In the example of three prisoners, the leader must flip the first switch down three times to be sure all prisoners have visited the room, twice for the two other prisoners and once more in case the switch was initially up.
Nguyên Phạm
Chọn một người làm mốc thôi. Vì quản tù sẽ dẫn từng tù nhân vào căn phòng nên chỉ cần chờ người được chọn ghé vào căn phòng lần 2 là được. Không có giới hạn về thời gian, cũn không có nói là không được vào lần 2