# Re: [Jprogramming] Quora problem

```Yes, you are right. I misread the question. But I think my solution can be
tweaked to get the correct answer:```
```
nr =: 3&=@:#@:~. *. -.@:(0&e.) NB. no repeats, and no zeros allowed.
(nr"1 # ] ) 10 10 10 #: i. 1000

I think this gives all permutations with no repeated digits. To integerify the
results just do
". (-.&' ')@:":"1

I think your method is nicer though.
--------------------------------------------
On Sat, 8/12/17, 'Mike Day' via Programming <programm...@jsoftware.com> wrote:

Subject: Re: [Jprogramming] Quora problem
To: programm...@jsoftware.com
Date: Saturday, August 12, 2017, 8:15 PM

I think Skip wants all
permutations, not just increasing and decreasing
ones,
so here's an
alternative:
5({.,(-@[){.])
10#.(#~(3=#@~.)"1) >: 9#.inv i. 9^3
123 124 125 126 127 983 984 985 986 987

The initial 5 ( ) is of course
just to limit the output!

Any use?
Mike

On 12/08/2017 10:56, 'Jon
Hough' via Programming wrote:
> Not
particularly efficient or terse but here:
>
> inc=:
-.@:(0&e.)@:~.@:(2&(</\)) NB. increasing
> dec=:
-.@:(0&e.)@:~.@:(2&(</\)) NB. decreasing
> mt=: inc +. dec NB. monotonic
>
>   (-:9*8) }.
(mt"1 # ] ) 10 10 10 #: i. 1000 NB. strip off the first
9*4 rows.
>
--------------------------------------------
> On Sat, 8/12/17, Skip Cave <s...@caveconsulting.com>
wrote:
>
>   Subject:
[Jprogramming] Quora problem
>   To:
"programm...@jsoftware.com"
<programm...@jsoftware.com>
>   Date: Saturday, August 12, 2017, 6:16
PM
>
>   How can
I use J to generate all the possible
>
3-digit integers that can be
>
constructed using the digits 1-9 (no
>
zeros), with no repeated digits in
>
each integer? The sequence starts with
>   123 (smallest) and goes to 987
>   (largest). Here's the first few
>   integers in the sequence:
>
>   123 124 125
126 127 128 129 132 134 135
>   136 137
138 139 142 143 145 146 147
>   148 149
152 153 154 156 157 158 159
>
162......
>
>
Skip
>
>   Skip
Cave
>   Cave Consulting LLC
>
----------------------------------------------------------------------
>   For information about J forums see http://www.jsoftware.com/forums.htm
>
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> For information about J forums see http://www.jsoftware.com/forums.htm

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