I think--although I am unclear on your question exactly--that you are
mixing up
(+/"1@({&f)@digits + [:(-~<./)grp) i.11
With
+/"1@({&f)@(digits + [:(-~<./)grp) i.11
In the second one, you would end up taking _1{f.
But in the first, you first take +/"1@({&f)@digits, which is the correct sum
with leading 0s. Then you subtract 1 for each leading 0 that you added 1
for. In this case, you never take _1{f, so it is unimportant.
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of gary ng
Sent: Monday, August 30, 2010 6:24 PM
To: Programming forum
Subject: Re: [Jprogramming] Splitting an integer into its digits
On Mon, Aug 30, 2010 at 8:22 AM, R.E. Boss <[email protected]> wrote:
> Further improvement:
> @({&f)@digits + [:(-~<./)grp) d'
thanks. After looking at this, I know better what Marshall was talking
about. However, there is still something that I don't quite understand
(digits + [:(-~<./)grp) i.11
_1 _1
_1 0
_1 1
_1 2
_1 3
_1 4
_1 5
_1 6
_1 7
_1 8
1 0
(+/"1@({&f)@digits + [:(-~<./)grp) i.11
0 0
0 1
0 3
0 8
0 27
0 124
0 725
0 5046
0 40327
0 362888
2 1
(+/"1@({&f)@digits + [:(-~<./)grp) i.11
1 2 4 9 28 125 726 5047 40328 362889 3
What would be the lookup result of _1 { f ? It shows 0 but if I just type -1
{ f, I get something else.
Also where does the extra +1 come from when I put back the +/"1 to the rank
1 row ?
Hope you don't mind for the questions.
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