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Runtime Error - Need Help

 
Greenhorn
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Hi all, I'm working on some code for an assignment and I'm receiving a runtime error. Our professor provided us with the I/O code for the program and we only had to complete the code for max_cycle_length(); I've attached the code below.

Can someone help me figure out what could be causing this error? I cannot figure it out; the code performs the calculations correctly, but I can't get the program to terminate without throwing an exception. Thanks for any help - let me know if I need to post more info.

 
author and iconoclast
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This program will stop when your "readLine" method returns null, which will happen on end-of-file. On Windows, you can type an end-of-file character using Ctrl-Z; on UNIX, Ctrl-D.

So two questions for you: first, what does max_cycle_length compute, exactly? And second, an instructor actually gave you the other code to use as scaffolding?
 
Amy Lee
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max_cycle_length() computes the maximum cycle length inclusive and between two integers based on the 3n + 1 problem (Collatz Problem - see MathWorld.com).

Yes, the instructor gave us all the I/O code. The only code block we had to write was max_cycle_length().

I typed in <Ctrl> + Z and got back a NumberFormatException. Previously, I tried typing in -1 and got back a NoSuchElementException. I also tried hitting <ENTER> and I got back a NoSuchElementException as well.

It seems no matter what I type in I get some sort of an exception.
 
Ranch Hand
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Can you please post the EXACT error message you recieve? This will include information that we need to be able to help you further.

Layne
 
Layne Lund
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Originally posted by Amy Lee:
...Yes, the instructor gave us all the I/O code. The only code block we had to write was max_cycle_length()....



I wonder why your instructor provided this code? The Java API already has a readLine() method in the BufferedReader class that is probably much more efficient than the implementation your instructor gave.

Layne
 
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