You have got to be kidding. That's not even close to a threat.
If he told the employer that he would turn them in to the BSA if they did it, that would be a threat.
And it sure isn't blackmail. It would be blackmail if they did install pirated software on the machines and then he told the employer he would keep his mouth shut in exchange for some amount of money or a promotion. But just warning the employer about it is not a threat.
Sheesh!
It is something the employer should know about since any of their employees could turn them in and receive a nice cash reward from the BSA for doing so. There's no threat involved unless he explicitly or implicitly tells them that he is going to turn them in if they do it.
To elaborate a bit, suppose a store used the RFID tags to ring up purchases at the store.
Your RFID reader would read various tags while you walk down the aisles of a store. Then, while you are near the checkout line, it would transmit them to a reader (it would have more distance than a passive tag) and provide the ids it read to the reader as if it were a tag. Someone standing in line to buy $25 worth of purchases would find the store rang it up to include two or three tvs, stereos, a dozen pairs of shoes,..., adding up to several thousand dollars.
They would, I assume, notice that something was wrong and might have to ring them all up several times before you move away and they get the correct value.
You might point out to them that all it takes is one disgruntled employee or ex-employee to make a complaint to the BSA (Business Software Alliance).
There is a bright spot, however. After they pay a few hundred thousand dollars to the BSA, they may be more willing to switch completely to open source software.
The only reason to use a goto is if you have a limited stack size and/or require very fast code, and you need to unwind from the middle of a function in a language which doesn't support exceptions.
A goto is appropriate whenever and wherever the use of it will result in better quality and more readable code. In most cases when used appropriately, a goto will result in a far lower incidence of "appalling code rot".
Of course, there are plenty of brainwashed programmers around who are completely incapable of making such a determination.
That was obviously meant as a simple example illustrating the use of a goto in that situation. Use that approach with a few more memory allocations and maybe open a few files, testing to make sure all memory allocations and file opens worked okay. Every if clause is going to have to undo everything done before before returning from the function.
At least that is better than the common approach of just not checking to see if the allocation succeeded.
Another good use of gotos is to escape from heavily nested code. Far too many programmers will try to play with the loop variables to exit from the loops and end up with very poor and hard to follow code as a result.
The worst programmers either have generally been scared off from using gotos or they use them stupidly.
The average programmers don't use gotos because someone might think they are incompetent.
The very best programmers use gotos whenever and wherever appropriate, just like any other tool and their code is all that much better as a result.
Re:This is (now) a famous number-theory integer!
on
Censoring a Number
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· Score: 1
Is the number copyrighted? Or just the representation in hexadecimal?
Are we free to express the number in the base of our choice other than base 16?
But the original question did not specify "number of trips". It used the phrase "Figure out a way, as effectivly as possible" and left the question of how to determine relative effectiveness open. Any good candidate should spell out his interpretation of that and be ready to justify that interpretation.
Of course, that doesn't spell out whether or not they want an efficient solution, a solution that comes up with a valid answer, or maybe a solution that arrives at the most correct answer. If they want the most correct answer, than maybe we might want to drop both marbles from the first floor, then the second floor, then the third,..., until they break. If one breaks but not the other, then we must consider the possibility that maybe the marble that broke was defective and doesn't represent the normal marble. Or maybe the one that broke was the normal marble and the one that didn't was unusually strong.
But that is not likely what they are looking for. It seems clear that their marbles are assumed to be of uniform quality and will always break when dropped from the critical floor.
If it were me climbing those steps, I'd define efficiency in terms of number of steps climbed. Even if you are taking an elevator up and down (unless you have an elevator that makes the trip between any two floors in an equal time, it will take longer to go to a higher floor than a lower floor and so the height of the floor would still matter.
By the way, I didn't say that having the marble bounce is twice as effective. I merely said that if the marble bounced back to the same height from which it was dropped (that is, 100% bounce), the solution would be much different than if it didn't bounce because you wouldn't have to go back down to get it.
I never claimed it was a complete answer and wouldn't accept it as a complete answer if I was the interviewer. But I would look more favorably on a candidate who brought it up as a possibility and then continued on to the far more probable case of a marble with a limited bounce.
I'd also look more favorable on a candidate who took into account that the marble would have a terminal velocity and adapt their algorithm. I wouldn't think that a marble dropped from the 100th floor would really have much more of an impact, if any, than one dropped from the 20th floor.
Do you really want a candidate who only considers the most obvious approach?
If you have 100% rebound and if the efficiency is based on the total vertical distance covered, then it is close to the most efficient because you would never have to backtrack.
You would end up climbing the precise distance to the floor at which the marble breaks, when dropped.
If efficiency is based on the number of drops involved or upon the number of trips up and down, then it wouldn't be the most efficient. Of course, without 100% rebound of the marble, I don't really see how one can argue that the number of trips up and down counts for more than the number of floors covered in those trips. For example, a trip to the 2nd floor is much less expensive than a trip to the 100th floor.
So the most efficient strategy strongly depends on the working definition of efficiency. But, I assume, that is considered to be part of the problem.
If the marble could rebound to 100% of the height dropped from, the search algorithm would be strictly linear in terms of the number of floors climbed since you wouldn't have to go back to the street each time to retrieve the marble.
Except that a Huffman coding would end up making the sort more difficult. It's much easier by keeping things on nice neat byte boundaries.
I assume that each telephone number would be inserted as it arrived just to simplify the sort a bit.
So you'd receive a telephone number, calculate where it goes into the table, decide whether you have a big gap requiring 6 bytes to insert (2 bytes for the zero offset (used as a flag) plus the entire number) or just a small offset that fits in 2 bytes, shift the rest of the table by that many bytes, insert the number, and adjust the next number. One might even shift back 2 bytes if the new number fell in what had been a gap of 65,536 or greater and resulted in two smaller offsets.
Of course, if this routine was to be used many, many times, one would want to be more efficient. For example, one could use the extra space that won't be needed to store the encoded list of numbers to do some things in small steps and move back into the proper position in the array. For example, one might add the numbers as they come in into a smaller list and then merge the list into the bigger list.
I had the same idea about using a bit map of the search space, but it was obvious that there wasn't enough memory for that approach.
I suspect that what would it would take to fit the one million telephone numbers into 2 MB of memory would be to store the first number and then the offset to the next number,..., and insert each item into memory as it comes in. It would be slow but could be speeded up by breaking it into groups.
Thus, if the first three numbers were 00000005, 00000088, 00001088, you would store them as 00000005, 83, 1000. Thus, 4 bytes, 1 byte, and 2 bytes. I would imagine that using 2 byte offsets would be best. If there was a gap between two consecutive numbers greater than 2 bytes, put in a gap value of 0 to indicate the end of one sequence and the beginning of another sequence.
That is, if the first six numbers were 00000005, 00000088, 00001088, 10001088, 10001100, 10001123, the stored sequence would be 00000005, 83, 1000, 0, 10001088, 12, 23 and would require 18 bytes instead of 24 bytes to store the 6 numbers individually.
If one could do the entire one million numbers without any big gaps of 65,536 or greater, the total space would be 2,000,002 bytes. Each gap of 65,536 or more would add 4 more bytes to the length -- two for the 0 to indicate a new sequence and 4 to store the entire number.
So let's assume that 2M bytes = 2^11 = 2,097,152 bytes. That would give us some breathing space, but not enough for a worst case since we could only handle 24,287 gaps of 65,536 or more between consecutive numbers.
A fresh out of high school graduate, yes. But a high school grad who has been in the indsutry working for 4-5 years? No. Most of the time, he'll wipe the floor with the college graduate.
That may be true for relatively mundane tasks, but not for something that requires more background knowledge of the subject matter.
For example, very few, if any, computer professionals without degrees are going to have any serious understanding of things like algorithmic complexity. The few who will understand it without college will have studied it on their own. Yet, above a certain minimal level, any serious developer had better have a better than minimal understanding of them.
Without that wider background, all you end up with is someone who is knowledgeable about their own area but will likely never go much beyond it.
As it is, too few computer professionals with degrees have an adequate understanding of the nature of what they are doing. What you end up with is a bunch of developers who insist on reinventing the wheel instead of using what is already well understood. And when they reinvent the wheel, they generally do so very, very badly.
A developer writing software for a company who would have full copyrights to the finished product would need to write everything from scratch.
He would not be able to use pieces of code he wrote elsewhere because of two reasons. First, he would have to give up ownership of the code. But that brings up the second, thornier problem -- if he had already used that code in a project for someone else, there might be potential serious license problems for his earlier customers.
If I hired a developer to write some code and he was going to keep ownership of the copyrights, I would require an explicit perpetual license that would allow me to use, modify, and distribute the code (possibly with much different license terms). That way, if he conveyed the copyrights to someone else, I would still have the license I may need. And he couldn't change his mind later about the license terms. This hasn't come up since I invariably write my own code.
There is a difference between "rejected" and "denied".
From the reading of the story, it is difficult to know which is which.
As an attorney explained elsewhere, a motion would be rejected for not complying with court rules. If the motion is denied, that is on the merits.
So if they were, in fact, rejected, then it may not have been necessary to read them because the lack of compliance with court rules could have already been noted.
The Mountain Meadows massacre of September 11, 1857 left between 100 and 140 people dead. See Mountain Meadows massacre.
There may have been worse that I don't know about.
There was also a worse school massacre on May 18, 1927 in Bath, Michigan that didn't involve firearms. A schoolboard member dynamited a school building killing 45 and injuring 58. See Bath school disaster
There was a similar incident reported in San Antonio several years ago (early 80s, if I remember correctly).
Someone called up a demolition company and arranged for the house at such and such an address to be demolished. When the homeowner came home from work, his house was a pile of rubble.
I think the demolition company's insurance had to cough up some serious money on that one.
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You have got to be kidding. That's not even close to a threat.
If he told the employer that he would turn them in to the BSA if they did it, that would be a threat.
And it sure isn't blackmail. It would be blackmail if they did install pirated software on the machines and then he told the employer he would keep his mouth shut in exchange for some amount of money or a promotion. But just warning the employer about it is not a threat.
Sheesh!
It is something the employer should know about since any of their employees could turn them in and receive a nice cash reward from the BSA for doing so. There's no threat involved unless he explicitly or implicitly tells them that he is going to turn them in if they do it.
To elaborate a bit, suppose a store used the RFID tags to ring up purchases at the store.
..., adding up to several thousand dollars.
Your RFID reader would read various tags while you walk down the aisles of a store. Then, while you are near the checkout line, it would transmit them to a reader (it would have more distance than a passive tag) and provide the ids it read to the reader as if it were a tag. Someone standing in line to buy $25 worth of purchases would find the store rang it up to include two or three tvs, stereos, a dozen pairs of shoes,
They would, I assume, notice that something was wrong and might have to ring them all up several times before you move away and they get the correct value.
What would really be fun is to have a little credit card sized radio that would play with the various RFID tags it found.
Put it in your pocket and then walk down the aisles of your local WalMart.
You might point out to them that all it takes is one disgruntled employee or ex-employee to make a complaint to the BSA (Business Software Alliance).
There is a bright spot, however. After they pay a few hundred thousand dollars to the BSA, they may be more willing to switch completely to open source software.
A goto is appropriate whenever and wherever the use of it will result in better quality and more readable code. In most cases when used appropriately, a goto will result in a far lower incidence of "appalling code rot".
Of course, there are plenty of brainwashed programmers around who are completely incapable of making such a determination.
That was obviously meant as a simple example illustrating the use of a goto in that situation. Use that approach with a few more memory allocations and maybe open a few files, testing to make sure all memory allocations and file opens worked okay. Every if clause is going to have to undo everything done before before returning from the function.
At least that is better than the common approach of just not checking to see if the allocation succeeded.
Another good use of gotos is to escape from heavily nested code. Far too many programmers will try to play with the loop variables to exit from the loops and end up with very poor and hard to follow code as a result.
The worst programmers either have generally been scared off from using gotos or they use them stupidly.
The average programmers don't use gotos because someone might think they are incompetent.
The very best programmers use gotos whenever and wherever appropriate, just like any other tool and their code is all that much better as a result.
Is the number copyrighted? Or just the representation in hexadecimal?
Are we free to express the number in the base of our choice other than base 16?
Enquiring minds want to know.
If Microsoft wants real security controls, maybe they should switch to Security Enhanced Linux.
But the original question did not specify "number of trips". It used the phrase "Figure out a way, as effectivly as possible" and left the question of how to determine relative effectiveness open. Any good candidate should spell out his interpretation of that and be ready to justify that interpretation.
..., until they break. If one breaks but not the other, then we must consider the possibility that maybe the marble that broke was defective and doesn't represent the normal marble. Or maybe the one that broke was the normal marble and the one that didn't was unusually strong.
Of course, that doesn't spell out whether or not they want an efficient solution, a solution that comes up with a valid answer, or maybe a solution that arrives at the most correct answer. If they want the most correct answer, than maybe we might want to drop both marbles from the first floor, then the second floor, then the third,
But that is not likely what they are looking for. It seems clear that their marbles are assumed to be of uniform quality and will always break when dropped from the critical floor.
If it were me climbing those steps, I'd define efficiency in terms of number of steps climbed. Even if you are taking an elevator up and down (unless you have an elevator that makes the trip between any two floors in an equal time, it will take longer to go to a higher floor than a lower floor and so the height of the floor would still matter.
By the way, I didn't say that having the marble bounce is twice as effective. I merely said that if the marble bounced back to the same height from which it was dropped (that is, 100% bounce), the solution would be much different than if it didn't bounce because you wouldn't have to go back down to get it.
I never claimed it was a complete answer and wouldn't accept it as a complete answer if I was the interviewer. But I would look more favorably on a candidate who brought it up as a possibility and then continued on to the far more probable case of a marble with a limited bounce.
I'd also look more favorable on a candidate who took into account that the marble would have a terminal velocity and adapt their algorithm. I wouldn't think that a marble dropped from the 100th floor would really have much more of an impact, if any, than one dropped from the 20th floor.
Do you really want a candidate who only considers the most obvious approach?
If you have 100% rebound and if the efficiency is based on the total vertical distance covered, then it is close to the most efficient because you would never have to backtrack.
You would end up climbing the precise distance to the floor at which the marble breaks, when dropped.
If efficiency is based on the number of drops involved or upon the number of trips up and down, then it wouldn't be the most efficient. Of course, without 100% rebound of the marble, I don't really see how one can argue that the number of trips up and down counts for more than the number of floors covered in those trips. For example, a trip to the 2nd floor is much less expensive than a trip to the 100th floor.
So the most efficient strategy strongly depends on the working definition of efficiency. But, I assume, that is considered to be part of the problem.
But that's the point.
If the marble could rebound to 100% of the height dropped from, the search algorithm would be strictly linear in terms of the number of floors climbed since you wouldn't have to go back to the street each time to retrieve the marble.
Except that a Huffman coding would end up making the sort more difficult. It's much easier by keeping things on nice neat byte boundaries.
I assume that each telephone number would be inserted as it arrived just to simplify the sort a bit.
So you'd receive a telephone number, calculate where it goes into the table, decide whether you have a big gap requiring 6 bytes to insert (2 bytes for the zero offset (used as a flag) plus the entire number) or just a small offset that fits in 2 bytes, shift the rest of the table by that many bytes, insert the number, and adjust the next number. One might even shift back 2 bytes if the new number fell in what had been a gap of 65,536 or greater and resulted in two smaller offsets.
Of course, if this routine was to be used many, many times, one would want to be more efficient. For example, one could use the extra space that won't be needed to store the encoded list of numbers to do some things in small steps and move back into the proper position in the array. For example, one might add the numbers as they come in into a smaller list and then merge the list into the bigger list.
I had the same idea about using a bit map of the search space, but it was obvious that there wasn't enough memory for that approach.
..., and insert each item into memory as it comes in. It would be slow but could be speeded up by breaking it into groups.
I suspect that what would it would take to fit the one million telephone numbers into 2 MB of memory would be to store the first number and then the offset to the next number,
Thus, if the first three numbers were 00000005, 00000088, 00001088, you would store them as 00000005, 83, 1000. Thus, 4 bytes, 1 byte, and 2 bytes. I would imagine that using 2 byte offsets would be best. If there was a gap between two consecutive numbers greater than 2 bytes, put in a gap value of 0 to indicate the end of one sequence and the beginning of another sequence.
That is, if the first six numbers were 00000005, 00000088, 00001088, 10001088, 10001100, 10001123, the stored sequence would be 00000005, 83, 1000, 0, 10001088, 12, 23 and would require 18 bytes instead of 24 bytes to store the 6 numbers individually.
If one could do the entire one million numbers without any big gaps of 65,536 or greater, the total space would be 2,000,002 bytes. Each gap of 65,536 or more would add 4 more bytes to the length -- two for the 0 to indicate a new sequence and 4 to store the entire number.
So let's assume that 2M bytes = 2^11 = 2,097,152 bytes. That would give us some breathing space, but not enough for a worst case since we could only handle 24,287 gaps of 65,536 or more between consecutive numbers.
That may be true for relatively mundane tasks, but not for something that requires more background knowledge of the subject matter.
For example, very few, if any, computer professionals without degrees are going to have any serious understanding of things like algorithmic complexity. The few who will understand it without college will have studied it on their own. Yet, above a certain minimal level, any serious developer had better have a better than minimal understanding of them.
Without that wider background, all you end up with is someone who is knowledgeable about their own area but will likely never go much beyond it.
As it is, too few computer professionals with degrees have an adequate understanding of the nature of what they are doing. What you end up with is a bunch of developers who insist on reinventing the wheel instead of using what is already well understood. And when they reinvent the wheel, they generally do so very, very badly.
With the proper assumption, you need only one marble.
Assume that the marbles rebound back to the same height from where they were dropped.
Start at the first floor.
Drop the marble. If it breaks, you are done. Otherwise, catch it on the rebound, go up one floor, and repeat.
They probably won't let you get by with such a simple assumption, though.
I probably first met Evan in about 1973 or 1974 and used to see him around regulary until about 1980.
He's no nut.
Evan Brown ran into this problem.
He lost his job and spent quite a while in court fighting it.
His contract used the word "inventions" instead of "idea" but they interpreted "invention" to include just about anything.
A developer writing software for a company who would have full copyrights to the finished product would need to write everything from scratch.
He would not be able to use pieces of code he wrote elsewhere because of two reasons. First, he would have to give up ownership of the code. But that brings up the second, thornier problem -- if he had already used that code in a project for someone else, there might be potential serious license problems for his earlier customers.
If I hired a developer to write some code and he was going to keep ownership of the copyrights, I would require an explicit perpetual license that would allow me to use, modify, and distribute the code (possibly with much different license terms). That way, if he conveyed the copyrights to someone else, I would still have the license I may need. And he couldn't change his mind later about the license terms. This hasn't come up since I invariably write my own code.
There is a difference between "rejected" and "denied".
From the reading of the story, it is difficult to know which is which.
As an attorney explained elsewhere, a motion would be rejected for not complying with court rules. If the motion is denied, that is on the merits.
So if they were, in fact, rejected, then it may not have been necessary to read them because the lack of compliance with court rules could have already been noted.
This was not the worst shooting in US history.
The Mountain Meadows massacre of September 11, 1857 left between 100 and 140 people dead. See Mountain Meadows massacre.
There may have been worse that I don't know about.
There was also a worse school massacre on May 18, 1927 in Bath, Michigan that didn't involve firearms. A schoolboard member dynamited a school building killing 45 and injuring 58. See Bath school disaster
Trained to be safe at higher speeds? Not hardly.
In some states, maybe all, ambulance drivers are basically given something like a 5 mph buffer.
I know of at least one town that reportedly tickets ambulance drivers for speeding in town.
In one city using photo-radar in the early 90s, all photos of police speeding were sent to the traffic sergeant.
If the officer wasn't on a legitimate, logged call at the moment, they got quite an ass chewing and a black mark in their personnel file.
The only thing I use the file sharing networks for is to download new images of FreeBSD and Linux using BitTorrent.
The last thing I want is a "similar" file.
What would be a "similar" file to a FreeBSD ISO? It would either be a corrupted file or one with an introduced exploit.
There was a similar incident reported in San Antonio several years ago (early 80s, if I remember correctly).
Someone called up a demolition company and arranged for the house at such and such an address to be demolished. When the homeowner came home from work, his house was a pile of rubble.
I think the demolition company's insurance had to cough up some serious money on that one.