Add to favorites interview questions (with answers)

A. Logical Reasoning
1. If you ask a worker to work for you for seven days, the reward for the worker is a golden stripe. Gold bars are evenly divided into seven connected segments.
You must give them a piece of gold at the end of each day. How do you give it to you if you just break it twice?
?
2. Cut a box of cake into eight parts and divide it into eight parts, but there must be one in the box.
3. James had a bridge and it was dark when crossing the bridge, so there must be lights. It takes one second for James to bridge the bridge,
It takes three seconds for James's younger brother, six seconds for James's father, eight seconds for James's mother, and 12 seconds for James's grandfather. Each
This bridge can have a maximum of two people, and the speed of the bridge depends on the least slow, and the light will be 30 seconds after it is ignited
Extinguish. Q: How does the James family bridge the bridge?
4. A group of people wear a hat on their heads. There are only black and white hats, black at least
There is one. Everyone can see the colors of others' hats, but not their own. The host will show you
Watch the hats on others' heads and turn off the lights. If someone thinks they are wearing black hats
A slap in the face. Turn off the light for the first time and there is no sound. So turn on the lights again. Let's check again. When the lights are turned off, the crow is still there.
Que silent. It was not until the third time that the light was turned off that there was a slap in the face. How many people are wearing black hats?
5. Estimate the quality of the CN Tower TV Tower.
6. There is a diamond in each elevator door from the first floor to the tenth floor. The diamond sizes are different. When you take the elevator from the first floor to the tenth floor, the elevator door on each floor will open once. You can only get a diamond once. How can you get the largest one?
7. the U2 choir will arrive at the concert venue within 17 minutes. On the way, they will have to cross a bridge. Four people will depart from the same end of the bridge. You have to help them reach the other end. The sky is dark, they only have one flashlight. At the same time, a maximum of two people can bridge the bridge together, while a flashlight must be held when crossing the bridge, so someone has to bring the flashlight back and forth to both ends of the bridge. A flashlight cannot be lost. Walking for four
The speed varies. If two people walk in the same way, the speed of the slow person prevails. Bono takes 1 minute to bridge the bridge, edge takes 2 minutes to bridge the bridge, Adam takes 5 minutes to bridge the bridge, and Larry takes 10 minutes to bridge the bridge. How do they bridge the bridge within 17 minutes?
8. It takes an hour to burn an uneven rope. How can I use it to determine a half hour?
9. Why is the lid of the sewer circular?

10. How many gas stations (CARs) are there in the United States )?
11. How can I divide 140 grams of salt into 50 and 90 grams of salt by using 7 grams and 2 grams of weight and one balance?
12. One train leaves Los Angeles at a rate of 15 kilometers per hour and goes straight to New York. The other train departs from New York to Los Angeles at a rate of 20 kilometers per hour. If there is a bird, the speed 30 kilometers away and the current start of the two trains, depart from Los Angeles, return after encountering another car, and then fly back and forth between the two trains in turn, there was a train on both sides of the straight track. How long did the bird fly?
13. You have two cans, 50 red balls and 50 blue balls. You can randomly select one and put a ball into the pot. How can you give the biggest chance to select a red ball? In your plan, what is the exact chance of getting a red ball?
14. Imagine that you are in front of the mirror. Why can't images in the mirror be upside down, but not upside down?
15. You have four pills in your can. Each pill has a certain weight. The contaminated pills are not contaminated. + 1. how can I determine which jar of medicine is contaminated once?
16. If you have an infinite amount of water, a 3-boast bucket and a 5-boast bucket, how can you accurately claim 4-boast of water?
17. You have a bucket of jelly, including yellow, green, and Red. Close your eyes and select two in the same color to capture the two in the same color. You can determine if you have two joos of the same color after capturing them?
18. Insert the car key into the door. In which direction can the car lock be turned on?
19. If you want to remove any of the 50 states, which one do you want to remove? Why?
20. For a batch numbered 1 ~ 100 switch all the lights on and off to perform the following operations
If the value of 1 is reversed, the value of 2 is reversed, and the value of 3 is reversed.
The number of the light in the closing status.
21. Assume that a disc is rotated as it is on a player. This disk is black and white. Suppose you have a limited number of color sensors. How many color sensors do you need to place around a disc to determine its rotation direction? Where should they be placed?
22. Assume that the clock reaches 12 o'clock. Note that the hour and minute hands overlap. How many times does the hour and minute hands overlap in a day? Do you know the specific time when they overlap?
23. The two odd numbers separated by only one digit are called odd pairs, such as 17 and 19. It is proved that the number between the odd pair can always be divided by 6 (assuming that both odd numbers are greater than 6 ). It is now proved that there are no odd pairs composed of three odd numbers.
24. A room has a door (the door is closed) and three electric lights. There are three switches outside the house, respectively connected to the three lights. You can manipulate these switches at will, but once you open the door, you cannot change the switch. Determine the light for each switch.
25. Suppose you have eight balls, one of which is slightly heavier, but the only way to find the ball is to place the two balls on the balance for comparison. How many times can I find the heavier ball?
26. Playing a word splitting game below will disrupt the order of all letters. You need to determine what the word is. Assume that the word to be split is composed of five letters:
1. How many possible combinations are there?
2. What if we know which five letters it is?
3. Find a solution to this problem.
27. Four women are planning a bridge. They all stood on one side of the bridge and wanted them to pass the bridge in 17 minutes. It is evening. They only have one flashlight. Only two people can bridge the bridge simultaneously. No matter who crosses the bridge, whether it is a person or two people, must carry a flashlight. The flashlight must be transmitted and cannot be thrown. The speed of a woman crossing a bridge is different. The speed of two people must be slow.
First woman: It takes 1 minute to bridge the bridge;
Second woman: It takes 2 minutes to bridge the bridge;
Third woman: It takes 5 minutes to bridge the bridge;
Fourth woman: it takes 10 minutes to bridge the bridge.
For example, if the first woman and 4th Women bridge the bridge first, it has been 10 minutes since they passed. If 4th Women are asked to send their flashlights back, then when she reaches the other end of the bridge, it will take 20 minutes in total, and the operation will fail. How can these four women bridge the bridge within 17 minutes? What other methods are there?
28. If you have two buckets, one with red paint and the other with blue paint. You pull a cup from the blue paint bucket, pour it into the red paint bucket, and then pull a cup from the red paint bucket into the blue paint bucket. Which of the two buckets has a higher ratio of red and blue pigments? This is proved by arithmetic means.

B: Crazy computing
29. Two 1-2 known ~ The number between 30. A knows the sum of two numbers, and B knows the product of two numbers.
A asked B: "Do you know which two numbers are there? "B said:" I don't know ";
B asked a: "Do you know which two numbers are there? "Jia said:" I don't know ";
So, B said, "Then I know ";
Then Jia also said, "Then I know ";
What are the two numbers?
30, 4, 4, 10, 10, plus, subtraction, multiplication, division, how do I get out of 24 points?
31, 1000! How many digits are there? Why?
32. F (n) = 1 n> 8 n <12
F (n) = 2 n <2
F (n) = 3 n = 6
F (n) = 4 N = Other
Use the +-*/and sign (n) functions to combine the F (n) function.
Sign (n) = 0 n = 0
Sign (n) =-1 n <0
Sign (n) = 1 n> 0
33. Compile a program for quality and for example, F (7) = 1 + 3 + 5 + 7 + 11 + 13 + 17 = 58
34 ,...
Draw four straight lines with only one pen to connect all the nine points
35. What are the types of layer-3 4 Binary Trees?
36. The 1--100000 series are arranged in a certain order. How can I correct a number? The best way to write. What about two numbers?
　　

 

Reference answer:
1. day1 to 1 segment,
Day2 asked the worker to return segment 1 to segment 2,
Day3 to 1 segment,
In day4, return segment 1 and segment 4.
Day5 and so on ......
2. In the face of such a strange question, some candidates cannot be divided with their brains, while some candidates feel
This question is actually very simple. Take out 7 of the eight slices of cake and divide the remaining one into the cake box.
For 8th People.
4. If only one person is wearing a black hat, then he sees everyone wearing a white hat. when the light is turned off for the first time
Should be self-slapped, so more than one person should wear black hats; if there are two black hats, the first time both
When I saw the black hat on the other party's head, I was not sure about my color. But when I switched off the light for the second time, the two should understand that
If you wear a white hat on your own, the other party should have slapped your face as early as the last time. Therefore, they also wear black hats.
As a result, there will also be a slap in the face; but the fact is that the third round of a slap in the face, it means that the audience is more than two blackers.
Caps, and so on, should be turned off several times, there are several black hats.
5. For example, how do you quickly estimate the height of the bracket and column, the ball radius, and the volume of each part?
. Recruitment Officer's statement: "For cntower, it is different from a general riddle or smart question.
. We call this kind of question 'quick estimation title' mainly to test the ability of quick estimation, which is to develop software.
One of the essential capabilities. Of course, the question is just a means, not a purpose. It is necessary to get a final result.
But more importantly, the process of obtaining this result is a method test. "Mr Miller
He gave an example to illustrate a reasonable answer. He first drew a sketch of CN Tower on paper, and then quickly
Estimate the height of the bracket and column, as well as the ball radius, calculate the volume of each part, and then run it with the density of each part.
Finally, a result is obtained by adding them.
There are actually many questions in this category, such as: "estimate the quality of water in the Mississippi River. "" If you
It's the governor of Tennessee. estimate how long it will take to manage the pollution of the Compaq River. "
"Estimate the quality of the rain that a person who travels in light rain will experience in 5 minutes. "
Mr Miller went on to explain: "questions like this, including some reasoning questions, are all taken by people.
Problemsolving (the ability to solve the problem), you can simply remember the answer. "
Mr Miller emphasized four points regarding the company's recruitment goals, which are widely noted by creative companies.
The quality of employees is the quality and ability that people who want to realize their dreams of career in well-known enterprises must possess.
Requirement 1: rawsmart (pure wisdom) is irrelevant to knowledge.
Requirement 2: Long-termpotential (long-term learning ability ).
Requirement 3: technicskills (skill ).
Requirement 4: professional attitude ).
6. Her answer is: if you choose not to take the first five floors, observe the diamond size of each layer and check the size of each layer.
. Select the next five floors, and select the diamond with the largest diamond size near the first five floors. So far
I don't know the exact answer to this question. "Maybe there is no accurate answer. I just want to test your ideas ."
.
7. analysis: a Cornell student wrote an article saying that he met this question during a Microsoft interview.
, Can only be made within 19 minutes.
8. Both sides are burned together.
9. One answer: the answer from a professor of computer science at the Massachusetts Institute of Technology is
In the case of other materials, his area is the largest. Second, if it's square, rectangular, or elliptical, it's boring.
When you pick it up, you can directly throw it into the underground road! But the circular lid can avoid this situation.
10. When this is a bit confusing, you may have to ask how small the country is.
Start with a car. The interviewer may tell you this number, but it may also say, "I don't know. Please tell me.
Me. "Then, you say to yourself that the population in the United States is 0.275 billion. You can guess that if the average
(Including Singleton) is 2.5 people. Your computer will tell you that there are 0.11 billion families in total. You recall
I have heard about where every household has 1.8 cars, so there will be about 0.198 billion cars in the United States.
Car. Next, as long as you figure out how many gas stations are needed to serve 0.198 billion cars, you can solve the problem.
Yes. What is important is not the number of gas stations, but the method for drawing this number.
12. The answer is easily calculated:
Assume that the distance from Los Angeles to New York is S.
The distance between the bird flight is (S/(15 + 20) * 30.
13. No answer. Check whether you have the courage to stick to your opinion.
14. Because the human eyes are symmetric horizontally.
15. extract one from the first box, two from the second box, and three from the third box.
And so on.
16. Complicated:
A. Use a 3-tier bucket to fill the bucket and pour it into 5-tier bucket. (3-> 5)
Mark B1 (B1 for short) in a bucket of 5 kubernetes ).
B. Use 3 to fill the filled water with 5 blank 3 to pour 5 water into 3 until B1 marks B2 in 3
C. Use 5 to fill the filled water with 3 blank 5 5 to 5 until B2
D. Empty 3. Pour 5 water into 3 and mark it as B3.
E. Fill in 5 blank 3 5 water 3 until 3 water to B3
Now, 5 water is the standard 4-boast dehydration.
20. The prime number is off, and the rest is on.
29. When two duplicates are allowed
The answer is x = 1, y = 4; A knows and A = x + y = 5, B knows the product B = x * Y = 4
Two answers are not allowed if two numbers are repeated.
Answer 1: x = 1, y = 6; A knows and A = x + y = 7, B knows product B = x * Y = 6
Answer 2: x = 1, y = 8; A knows and A = x + y = 9, B knows product B = x * Y = 8
Solution:
Set these two numbers to X, Y.
A knows the sum of the two numbers a = x + y;
B knows the product B = x * y of the two numbers;
This question is divided into two situations:
Repeat allowed, with (1 <= x <= Y <= 30 );
Repeat is not allowed, with (1 <= x <Y <= 30 );
If the repeat is not allowed, that is, (1 <= x <Y <= 30 );
1) Question Setting condition: B does not know the answer
<=> B = x * y the solution is not unique.
=> B = x * Y is a non-prime number.
∵ X = y
∴ B = K * K (where K is N)
Conclusion (inference 1 ):
B = x * y non-prime number and B = K * K (where K is N)
That is: B, (6, 8, 10, 12, 14, 15, 18, 20 ...)
The verification process is omitted.
2) Question Setting condition: A does not know the answer
<=> A = x + y is not unique
=> A> = 5;
There are two situations:
A = 5, a = 6 X, Y has a dual solution
A> = x, y has three or more solutions
Suppose a = x + y = 5
There is a dual solution
X1 = 1, Y1 = 4;
X2 = 2, y2 = 3
Input formula B = x * Y:
B1 = x1 * Y1 = 1*4 = 4; (excluding inference 1)
B2 = x2 * y2 = 2*3 = 6;
Obtain the unique solution x = 2 and Y = 3, that is, Jia knows the answer.
It is in conflict with the question: "A does not know the answer,
Therefore, the assumption is not true. A = x + y = 5
Suppose a = x + y = 6
There is a dual solution.
X1 = 1, Y1 = 5;
X2 = 2, y2 = 4
Input formula B = x * Y:
B1 = x1 * Y1 = 1*5 = 5; (do not satisfy inference 1, remove)
B2 = x2 * y2 = 2*4 = 8;
Obtain the unique solution x = 2, y = 4.
That is, Jia knows the answer.
It is in conflict with the question: "A does not know the answer"
Therefore, the assumption is not true. A = x + y = 6
When a> = 7
There are at least two solutions for the solutions between x and y that satisfy inference 1.
B1 = x1 * Y1 = 2 * (A-2)
B2 = x2 * y2 = 3 * (A-3)
Condition
Conclusion (inference 2): A> = 7
3) Question Setting condition: "I know", said B"
=> B obtains the unique solution through the known condition B = x * Y and inference (1) (2 ).
That is:
A = x + y, A> = 7
B = x * y, B '(6, 8, 10, 12, 14, 15, 16, 18, 20 ...)
1 <= x <Y <= 30
X and Y have unique solutions.
When B = 6: There are two groups of solutions
X1 = 1, Y1 = 6
X2 = 2, y2 = 3 (optional X2 + y2 = 2 + 3 = 5 <7)
Obtain the unique solution x = 1, y = 6.
When B = 8: There are two groups of solutions
X1 = 1, Y1 = 8
X2 = 2, y2 = 4 (optional X2 + y2 = 2 + 4 = 6 <7)
Obtain the unique solution x = 1, y = 8.
When B> 8: it is easy to prove multiple solutions.
Conclusion:
When B = 6, there is a unique solution x = 1, y = 6. When B = 8, there is a unique solution x = 1, y = 8.
4) Question Setting condition: A said, "I know it too"
=> Jia can obtain the unique solution through the known condition A = x + y and inference (3 ).
To sum up, there are two groups of solutions for the original question:
X1 = 1, Y1 = 6
X2 = 1, y2 = 8
When X is <= Y, there are (1 <= x <= Y <= 30 );
Similarly, we can obtain the unique solution x = 1, y = 4.
31. Solutions: 1000
LG (1000 !) = Sum (lg (n ))
N = 1
We can use three broken lines to replace the curve.
10 (0 + 1)/2 + 90 (1 + 2)/2 + 900 (2 + 3)/2 = 2390
As an approximate result, it seems like 1500 ~ 3000
32. F (n) = 1 n> 8 n <12
F (n) = 2 n <2
F (n) = 3 n = 6
F (n) = 4 N = Other
Use the +-*/and sign (n) functions to combine the F (n) function.
Sign (n) = 0 n = 0
Sign (n) =-1 n <0
: Sign (n) = 1 n> 0
Solution: you only need to pay attention to [sign (n-m) * sign (m-n) + 1] Getting 1 AT n = m and getting 0 from other points.
34. Just draw the meters.