I have put my solution to this problem in
http://code.jsoftware.com/wiki/Essays/PropagatingMinimum
The details are a little different, but the basic idea is the same.
Henry Rich
On 3/2/2016 3:15 PM, Brian Schott wrote:
Oops, I forgot to enter "the following sentence":
expand;<./@lineup each
sorry if this has been answered already,
>@(~.@[ ; each
To: programm...@jsoftware.com
Sent: Friday, March 4, 2016 4:34 AM
Subject: Re: [Jprogramming] J Challenge
I don't think for a minute that this will be the most terse or most elegant but
this is what I got:
animals =:
'bird';'cow';'cow';'
not as concise, but an alternative:
makeTable =: ( ((<0;0)&{:: ; ( wrote:
> I'd have used ;:inv instead of ;:^:_1 like EelVex used (same
> operation, but slightly shorter and I think slightly easier to read).
>
> Generally, ;:inv is perfect for taking a boxed list of strings and
> getting a space
I'd have used ;:inv instead of ;:^:_1 like EelVex used (same
operation, but slightly shorter and I think slightly easier to read).
Generally, ;:inv is perfect for taking a boxed list of strings and
getting a space separated string.
Commas are a bit more work (and if you want the last comma to be
(~.@{.,.<@(;:^:_1)/./)list2
┌┬─┐
│bird│one eight fourteen │
├┼─┤
│cow │two three five six seven │
├┼─┤
│dog │four nine eleven thirteen│
├┼─┤
│cat │ten │
├───
Both Henry &
Raul came up with
what is
likely the shortest solution:
(~.@[ ,. [/.)/ list
I like Henry's second approach, even though it is a bit longer:
(~.@[ ,. <@;/.)/ list
┌┬─┐
│bird│1 8 14 │
├┼─┤
│cow │2 3 5 6 7│
├┼─┤
│dog │4 9 11 1
I use a verb called (readtd2) for this: The tacit defn is (all that follows
is one line which
email typically mangles):
NB. read TAB delimited table files - faster than (readtd) - see long
document
readtd2=:[: <;._2&> (9{a.) ,&.>~ [: <;._2 [: (] , ((10{a.)"_ = {:) }.
(10{a.)"_) (13{a.) -.~ 1!:1&(
I came up with basically the same thing Henry came up with:
list=: (,: <@#\) ;:0 :0 -.LF
bird cow cow dog cow cow cow bird
dog cat dog pig dog bird pig
)
(~.@[ ,. [/.)/list
┌┬──┬──┬──┬──┬─┐
│bird│1 │8 │14│ │ │
├┼──┼──┼──┼──┼─┤
│cow │2 │3 │5 │6 │7│
├┼──┼──┼──┼──┼─┤
│dog │4 │9 │11
animals =:
'bird';'cow';'cow';'dog';'cow';'cow';'cow';'bird';'dog';'cat';'dog';'pig';'dog';'bird';'pig'
ids =: 1;2;3;4;5;6;7;8;9;10;11;12;13;14;15
t =. animals,:ids
(~.@[ ,. ]/.)/ t
++--+--+--+--+-+
|bird|1 |8 |14| | |
++--+--+--+--+-+
|cow |2 |3 |5 |6 |7|
++--+--+--+--+-+
|
I guess the input needs to be
animals ,: ids
so...
ai =: animals ,: ids
f2 =: (1&{) f (0&{) NB. f same as previous answer.
f2 ai
I guess that's not really "one expression" now, so
f2 =: 1&{ (((1 ,~ #) $ ])@:~.@:] ,. ]/.~) 0&{
On Fri, 3/4/16, 'J
I don't think for a minute that this will be the most terse or most elegant but
this is what I got:
animals =:
'bird';'cow';'cow';'dog';'cow';'cow';'cow';'bird';'dog';'cat';'dog';'pig';'dog';'bird';'pig'
ids =: 1;2;3;4;5;6;7;8;9;10;11;12;13;14;15
f =: (((1,~ #) $])@:~.@:]) ,. (]/.)~
ids f ani
Well, the format of that last post was a bit messy. Here's a second try:
The
animal control officer wants to keep track of the animals in a city.
The officer tags all the animals with a serial number.
He keeps a list of all the animals he has tagged, along with each serial
number.
list
The
animal control officer wants to keep track of the animals in a city.
The officer tags all the animals with a serial number.
He keeps a list of all the animals he has tagged, along with each serial
number.
list
┌┬───┬───┬───┬───┬───┬───┬┬───┬───┬───┬───┬───┬┬───┐
│
bird
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