More relevant than > parents ,n ,: n treesum parents > 0 0 1 2 2 3 3 4 4 4 > 46 25 101 69 102 9 58 45 40 64 > 559 513 488 136 251 9 58 45 40 64
seems to me (i.#n) ,n ,: n treesum parents 0 1 2 3 4 5 6 7 8 9 46 25 101 69 102 9 58 45 40 64 559 513 488 136 251 9 58 45 40 64 R.E. Boss > -----Oorspronkelijk bericht----- > Van: [EMAIL PROTECTED] [mailto:programming- > [EMAIL PROTECTED] Namens Raul Miller > Verzonden: dinsdag 11 maart 2008 20:55 > Aan: Programming forum > Onderwerp: [Jprogramming] tree sum and difference > > So, let's say that I have a tree structure where 0 > is the parent of all other nodes > parents=: p:inv 1+i.10 > and that I have some numbers associated with > the nodes of this tree > n=: ?.100+i.10 > > I can produce a tree-wise sum, for example: > connmat=:3 :'(e."0 1/ [:|:{&y^:a:)i.#y' > treesum=: +/ .* |:@connmat > parents,n,:n treesum parents > 0 0 1 2 2 3 3 4 4 4 > 46 25 101 69 102 9 58 45 40 64 > 559 513 488 136 251 9 58 45 40 64 > > I can also find the tree-wise difference, for example: > treediff=: %. connmat > 559 513 488 136 251 9 58 45 40 64 treediff parents > 46 25 101 69 102 9 58 45 40 64 > > However, it seems that there ought to be faster > approaches for large trees (with hundreds or > thousands of nodes). > > So, since some people like puzzles, can anyone > come up with faster implementations for treesum > and treediff, for large trees? > > Thanks, > > -- > Raul > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
