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|
(* tree.sml
*
* COPYRIGHT (c) 1994 AT&T Bell Laboratories.
*
* Trees for the TSP program.
*)
structure Tree =
struct
datatype tree
= NULL
| ND of {
left : tree, right : tree,
x : real, y : real,
sz : int,
prev : tree ref, next : tree ref
}
fun mkNode (l, r, x, y, sz) = ND{
left = l, right = r, x = x, y = y, sz = sz,
prev = ref NULL, next = ref NULL
}
fun printTree (outS, NULL) = ()
| printTree (outS, ND{x, y, left, right, ...}) = (
TextIO.output(outS, String.concat [
Real.toString x, " ", Real.toString y, "\n"]);
printTree (outS, left);
printTree (outS, right))
fun printList (outS, NULL) = ()
| printList (outS, start as ND{next, ...}) = let
fun cycle (ND{next=next', ...}) = (next = next')
| cycle _ = false
fun prt (NULL) = ()
| prt (t as ND{x, y, next, ...}) = (
TextIO.output(outS, String.concat [
Real.toString x, " ", Real.toString y, "\n"
]);
if (cycle (!next))
then ()
else prt (!next))
in
prt start
end
end;
|
