[mercury-users] Programming "contests".

[Gustavo A. Ospina]

Good day to all:

I don't think that there are inconvenient in using this maillist to
discuss the "contests" of programming. I believe that makes part of the
philosophy of this list. Though if you want to separate the operative
discussions about Mercury (compiler, announcements, etc) from the
discussions about programming as these challenges, the Mercury team would
create other maillist that would be called "mercury-programming", or so.

With respect to the problem of collect_pairs, I think that the solution
proposed by Andrew is the most elegant of all. To use stacks is it more
efficient and not use a double recursion.

I would change only two things to the solution:

- Instead of using two tree stacks, I would use only an stack of tree 
pairs.

- I would use my undefined type (or add the term 'undefined' on definition
of type tselem) to handle non isomorphic trees. I think that this would be
useful if is thought about reconstructing the two trees as of the pairs
list. This would be possible if the trees are ordered.

I want advantage this opportunity to ask a operative question on something
that me has very intrigued:

What really happens when upon installing Mercury compiler occurs this 
error?:

	Internal Compiler Error: program cc1 got fatal signal 4

It is a bug of gcc? of Linux kernel? I don't know...

This error occurs me frequently upon installing Mercury compiler (version 
0.6 and 0.7.3 in Linux 2.0.0 using gcc 2.7.2). I had to restart several
times 'make' to continue and finish with the installation.

Thanks a lot and have a nice day and regards.

+ Gustavo.

	+---------------------------------------+
	|  Gustavo A. Ospina                    |
	|  MSc Student                          |
	|  Computing and Systems Engineering    |
	|  University of Los Andes              |
	|  Santafe de Bogota D.C., Colombia     |
	|  e-mail: g-ospina at uniandes.edu.co     |
	+---------------------------------------+