Discussion

Eduard Lebedyuk · Feb 2, 2022

#Code Golf #Code Snippet #InterSystems IRIS

You will receive a string of comma-separated integers whose elements have both a negative and a positive value, except for one integer that is either only negative or only positive, our challenge will be to find that integer.
As usual shortest solution wins.

Input

"1,-1,2,-2,3"

Output

3

3 has no matching negative appearance

Note

The only-positive or only-negative integer may appear more than once
Use this code to check the result length
You also can use this test case here

Rules

The signature of the contest entry MUST be:

Class CodeGolf.PairedOpposites
{

ClassMethod Solve(o As %String) As %Integer
{
}

}

It is forbidden to modify class/signature, including but not limited to:

Adding inheritance
Setting default argument values
Adding class elements (Parameters, Methods, Includes, etc).

It is forbidden to refer to non-system code from your entry. For example, this is not a valid entry:

ClassMethod Solve(o)
{
  q ##class(myPackage.myClass).test(o)
}

The use of $ZWPACK and $ZWBPACK is also discouraged.

Discussion (34)1

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Robert Cemper · Feb 2, 2022

Special thanks for defining the clear rules and excluding 'dirty' tricks

1 0

Alexey Maslov · Feb 2, 2022

Straightforward one of 85 characters:

ClassMethod Solve(o As %String) As %Integer
{
  f i=1:1:$l(o,","){s x=$p(o,",",i) i $d(y(-x)){k y(-x)}else{s y(x)=1}} q $o(y(""))
}

1 0

George James · Feb 2, 2022

q @$tr(o,",","+")

3 0

George James · Feb 2, 2022

Of course, this solution does not implement the rule "The only-positive or only-negative integer may appear more than once" :(

0 0

Robert Cemper · Feb 2, 2022

and you get 0 if numbers are paired !

0 0

George James · Feb 2, 2022

I think the problem as stated implies that there will always be at least one unpaired number: "... except for one integer that is either only negative or only positive"

1 0

Eduard Lebedyuk · Feb 2, 2022

Clever!

If only there was a way to get "remaining parts" length, in that case we could divide the sum you've got by a number of repetitions and get the answer.

1 0

Stuart Strickland · Feb 2, 2022

ClassMethod Solve(o As %String) As %Integer

{

s i=$l(o,","),j=$l(o,"-")-1,k=i-j-j s:k<0 k=k-j-j s m=$tr(o,",","+")_"/"_k

q @m

}

1 0

Stuart Strickland · Feb 2, 2022

Add's to GJ's effort and counts how many occurrences of the odd integer to be able to return exact answer (not a $ZABS answer).

0 0

George James · Feb 3, 2022

Sadly, this solution doesn't quite work for negative unpaired integers. For example "1,-1,-2"

0 0

George James · Feb 3, 2022

 q @($tr(o,",","+")_"/"_$zabs(2*$l(o,"-")-$l(o,",")-2))

1 0

Stuart Strickland · Feb 3, 2022

Superb!

0 0

Robert Cemper · Feb 2, 2022

size = 65 return 0 if all pared; { 0 is excluded for pairing }

ClassMethod Solve(o As %String) As %Integer
{
 s y=$lfs(o) f i=1:1:$ll(y) s c=$li(y,i) ret:'$lf(y,-c) c
 q 0
}

3 0

Eduard Lebedyuk · Feb 2, 2022

49 as we can iterate numbers, not list elements:

ClassMethod Solve(o As %String) As %Integer
{
 s y=$lfs(o) f i=-9:1 ret:$lf(y,i)&&'$lf(y,-i) i
}

0 0

Robert Cemper · Feb 2, 2022

NICE. but runs forever if there is no unpared.
And why starting with -9 ?

0 0

Eduard Lebedyuk · Feb 2, 2022

And why starting with -9 ?

Considering we need to hit anything from -9 to 9 where else should I start?

0 0

Robert Cemper · Feb 2, 2022

but it fails if the unpaired is < -9 as in the ref.example

"-110,110,-38,-38,-62,62,-38,-38,-38" and doesn't stop

0 0

Robert Cemper · Feb 2, 2022

this works unlimited but has no exit if none unmatched found
method length = 64,
and it shows only the abs. value 38 instead of -38

s y=$lfs(o) f i=1:1 s a=$lf(y,i),b=$lf(y,-i) ret:a+b&'(a*b) i

0 0

George James · Feb 2, 2022

Or

s y=$lfs(o) f i=1:1 ret:'$lf(y,i)+'$lf(y,-i)=1 i

...but this still only returns the absolute value, so not a valid solution either.

0 0

Eduard Lebedyuk · Feb 4, 2022

Yes, looked promising but there are issues as we cant iterate positive/negative: 1,-1,2,-2 and so on.

0 0

Julius Kavay · Feb 2, 2022

Is "1,-1,1" a valid input sequence?

0 0

Eduard Lebedyuk · Feb 2, 2022

No, there's no number without the opposite.

0 0

Paul Collins · Feb 2, 2022

size 62

Class CodeGolf.PairedOpposites
{ ClassMethod Solve(o As %String) As %Integer
{
s res=0 f i=1:1:$l(o,",") s res=$p(o,",",i)+res q res
} }

0 0

Alexey Maslov · Feb 3, 2022

Even if correct the syntax error occurred due to COS Syntax highlight:

 s res=0 f i=1:1:$l(o,",") s res=$p(o,",",i)+res
 q res

it fails on Ed's samples #3, 4, 5 as it summarizes unpaired numbers:

1,-1,2,-2,3,3 returns 6 vs 3
-110,110,-38,-38,-62,62,-38,-38,-38 returns -190 vs -38
-9,-105,-9,-9,-9,-9,105 returns -45 vs -9

0 0

Vitaliy Serdtsev · Feb 3, 2022

It is a pity that the author left the previous task (Code Golf - Encoder) without attention, and the community ignored her (or did not notice;)

0 0

Vitaliy Serdtsev · Feb 3, 2022

size = 49

ClassMethod Solve(o As %String) As %Integer
{
 f i=1:1 s c=$p(o,",",i) ret:'$lf($lfs(o),-c) c
}

5 0

Robert Cemper · Feb 3, 2022

GREAT ! covers all situations.

0 0

Alexey Maslov · Feb 3, 2022

48! while all applauds are still to Vitaly.

ClassMethod Solve(o As %String) As %Integer
{
a s c=$p(o,",",$i(i)) q:'$lf($lfs(o),-c) c g a
}

4 0

Vitaliy Serdtsev · Feb 3, 2022

Good trick!

size = 47

ClassMethod Solve2(o As %String) As %Integer
{
a s c=$p(o,",",$i(i)) g:$lf($lfs(o),-c) a q c
}

3 0

David Underhill · Feb 9, 2022

43, shortening of Vitaliy's

ClassMethod Solve2(o As %String) As %Integer
{
 f  s c=$p(o,",",$i(i)) q:'$lf($lfs(o),-c) c
}

George James' solution is brilliant though.

0 0

Robert Cemper · Feb 9, 2022

FOR loop does not accept a quit with argument.

ERROR: CodeGolf.CHK.cls(7) :QUIT with arguments not allowed here c

but return is 5 chars more

0 0

David Underhill · Feb 9, 2022

Whoops I was in a rush and did a command line test, stupid.

0 0

Eduard Lebedyuk · Feb 9, 2022

ret is a valid shorthand for return, so it's only +2 characters totaling 45.

2 0

Vitaliy Serdtsev · Feb 9, 2022

I decided to check the size of the code using an officially allowed method.

ClassMethod length(
  class = {$classname()},
  method = "Solve") As %Integer [ CodeMode = expression ]
{
##class(%Dictionary.MethodDefinition).IDKEYOpen(class, method).Implementation.Size
}

So,

size = 46 (43)

ClassMethod Solve(o As %String) As %Integer
{
 f  s c=$p(o,",",$i(i)) q:'$lf($lfs(o),-c) c
}

size = 48 (45)

ClassMethod Solve(o As %String) As %Integer
{
 f  s c=$p(o,",",$i(i)) ret:'$lf($lfs(o),-c) c
}

1 0