Talk:Modular arithmetic: Difference between revisions

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The task description begins with:
<pre>
The purpose of this task is to show, if your programming language allows it,
how to redefine operators so that they can be used transparently on modular
integers. You can do it either by using a dedicated library, or by implementing your own class.
</pre>
This is a nice interesting task description - although it would be much more interesting
if one can't use a library. The interesting part in my view is how to redefine
operators. Allowing implementations to use a library hides the interesting part.

The task description ends with:
The task description ends with:
<pre>
<pre>
Line 5: Line 15:
In other words, the function is an algebraic expression that could be used with any ring, not just integers.
In other words, the function is an algebraic expression that could be used with any ring, not just integers.
</pre>
</pre>

For languages that represent elements in, says, Z/5Z as the integers 0,1,2,3,4 there is no way to
For languages that represent elements in, says, Z/5Z as the integers 0,1,2,3,4 there is no way to
distinguish an element of Z/5Z from n element in Z. This is slightly annoying since the remainder
distinguish an element of Z/5Z from n element in Z. That is, one is forced not to use existing libraries.
This will make functional solutions to this task look longer than object oriented languages.
of the task is interesting in its own right.

I therefore suggest that *all* solutions should show how to redefine operators/numbers without
using existing libraries.

Revision as of 21:29, 11 March 2013

The task description begins with:

The purpose of this task is to show, if your programming language allows it, 
how to redefine operators so that they can be used transparently on modular
 integers. You can do it either by using a dedicated library, or by implementing your own class.

This is a nice interesting task description - although it would be much more interesting if one can't use a library. The interesting part in my view is how to redefine operators. Allowing implementations to use a library hides the interesting part.

The task description ends with:

    It is important that the function f is agnostic about whether or not its argument is modular. 
    It should behave the same way with normal and modular integers. 
    In other words, the function is an algebraic expression that could be used with any ring, not just integers.

For languages that represent elements in, says, Z/5Z as the integers 0,1,2,3,4 there is no way to distinguish an element of Z/5Z from n element in Z. That is, one is forced not to use existing libraries. This will make functional solutions to this task look longer than object oriented languages.

I therefore suggest that *all* solutions should show how to redefine operators/numbers without using existing libraries.