Looks like you just need to
flip each pair in path from old root to new root
|: t1 (|."[EMAIL PROTECTED])}~ c i. }: (p {~ c i. ])^:(c e.~])^:a: 3
1 0 3 2 2 3 3 4 4 4 4 5 5 6 6 6 6 7 7
0 2 1 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
tree t1 (|."[EMAIL PROTECTED])}~ c i. }: (p {~ c i. ])^:(c e.~])^:a: 3
+----------------------------------+
| +- 8 |
| +- 9 |
| +- 4 -+- 10|
| | +- 11|
| +- 1 --- 0 --- 2 -+ +- 12|
| | +- 5 -+- 13|
| | +- 14 |
| | +- 15 |
|- 3 -+- 6 -+- 16 |
| | +- 17 |
| | +- 18 |
| +- 7 -+- 19 |
+----------------------------------+
--- On Mon, 5/19/08, Jose Mario Quintana <[EMAIL PROTECTED]> wrote:
> From: Jose Mario Quintana <[EMAIL PROTECTED]>
> Subject: Re: [Jprogramming] Displaying trees - J Wiki/Essays/Tree Sum
> To: "Programming forum" <[email protected]>
> Date: Monday, May 19, 2008, 12:12 PM
> A directed tree can be rerooted at any of its nodes. For
> example, t1 from
> http://www.jsoftware.com/jwiki/Essays/Tree_Display ,
>
>
> |:t1
> 0 0 1 2 2 3 3 4 4 4 4 5 5 6 6 6 6 7 7
> 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
> tree t1
> +----------------------------+
> | ┌─ 14|
> | ├─ 15|
> | ┌─ 6 ─┼─ 16|
> | │ └─ 17|
> | ┌─ 1 ─── 3 ─┤ ┌─ 18|
> | │ └─ 7 ─┴─ 19|
> | │ ┌─ 8 |
> |─ 0 ─┤ ├─ 9 |
> | │ ┌─ 4 ─┼─ 10 |
> | │ │ └─ 11 |
> | └─ 2 ─┤ ┌─ 12 |
> | └─ 5 ─┴─ 13 |
> +----------------------------+
>
> Can be rerooted at 3 as,
>
> tree t2=. 3 reroot t1
> +----------------------------------+
> | ┌─ 14 |
> | ├─ 15 |
> | ┌─ 6 ─┼─ 16 |
> | │ └─ 17 |
> | │ ┌─ 18 |
> | ├─ 7 ─┴─ 19 |
> |─ 3 ─┤ ┌─ 8 |
> | │ ├─ 9 |
> | │ ┌─ 4 ─┼─ 10|
> | │ │ └─ 11|
> | └─ 1 ─── 0 ─── 2 ─┤ ┌─ 12|
> | └─ 5 ─┴─ 13|
> +----------------------------------+
>
> |:t2 NB. (reroot rendering t2 or equivalent)
> 3 3 6 6 6 6 7 7 3 1 0 2 2 4 4 4 4 5 5
> 6 7 14 15 16 17 18 19 1 0 2 4 5 8 9 10 11 12 13
>
>
> Has any J version of reroot been made public already?
>
>
> ----- Original Message ----
> From: Roger Hui <[EMAIL PROTECTED]>
>
> Nothing new under the sun.
> http://groups.google.com/group/comp.lang.apl/browse_thread/thread/5f1c1df7bd72fe51/32691205433c3152?lnk=gst#32691205433c3152
>
> ----- Original Message -----
> From: Roger Hui <[EMAIL PROTECTED]>
>
> > http://www.jsoftware.com/jwiki/Essays/Tree_Display
> >
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