# [plt-scheme] (Slightly Off) Looking for a Sorting Algorithm

On Sun, 2005-11-20 at 17:36 +0100, Erich Rast wrote:
. . .
>* My original idea was to first sort the list such that it satisfies the
*>* rules, i.e. get one solution, and then determine the sublists that can
*>* be permuted without violating a rule and permute these lists whenever
*>* an output is needed. But by now I believe using a generic search
*>* algorithm won't help much.
*
Perhaps a topological sort could be used to provide the first
permutation that satisfies the rules, followed by a backtracking
algorithm working off that first permutation to generate the remaining
permutations.
It does appear that "x < y" rules define something close to a partial
order on labels, which is the hallmark of topological sort.
-- Bill Wood