Forum: Ruby Shortest code

hi i'm a newbie in ruby and was test out some interesting problems in
ruby,

i came across a small one to print the sum of positive numbers from a
list of n numbers... with the shortest code possible..

well the best i could do was,
puts gets.split(' ').inject(0){|sum,x| x.to_i>0?sum+x.to_i : sum}

is there a shorter version?

On Mon, Mar 8, 2010 at 10:10 PM, Prasanth Ravi <dare.take@gmail.com> 
wrote:
> hi i'm a newbie in ruby and was test out some interesting problems in
> ruby,
>
> i came across a small one to print the sum of positive numbers from a
> list of n numbers... with the shortest code possible..
>
> well the best i could do was,
> puts gets.split(' ').inject(0){|sum,x| x.to_i>0?sum+x.to_i : sum}
I am afraid so
puts gets.split.map(&:to_i).inject(&:+)
although in Ruby 1.8 you need
gets.split.inject(0){ |sum, x | sum + x.to_i }
or
   ... inject{ | sum, x | sum.to_i + x.to_i }
if you prefer.

What do *you* think is the most readable solution BTW ;)?

Cheers
Robert

P.S.
BTW if you meant to not use negative numbers (sorry my English is very 
basic)

map(&:to_i).select{ |x| x > 0 }. ...

would be my choice.

R.

Robert Dober wrote:
> On Mon, Mar 8, 2010 at 10:10 PM, Prasanth Ravi <dare.take@gmail.com> 
> wrote:
>> hi i'm a newbie in ruby and was test out some interesting problems in
>> ruby,
>>
>> i came across a small one to print the sum of positive numbers from a
>> list of n numbers... with the shortest code possible..
>>
>> well the best i could do was,
>> puts gets.split(' ').inject(0){|sum,x| x.to_i>0?sum+x.to_i : sum}
> I am afraid so
> puts gets.split.map(&:to_i).inject(&:+)
> although in Ruby 1.8 you need
> gets.split.inject(0){ |sum, x | sum + x.to_i }
> or
>    ... inject{ | sum, x | sum.to_i + x.to_i }
> if you prefer.
> 
> What do *you* think is the most readable solution BTW ;)?
> 
> Cheers
> Robert
> 
> P.S.
> BTW if you meant to not use negative numbers (sorry my English is very 
> basic)
> 
> map(&:to_i).select{ |x| x > 0 }. ...
> 
> would be my choice.
> 
> R.

tx for the reply, i originally used
y=0
gets.split.each{ |x|
  z=x.to_i
  y+=z if z>0
}
print y

--46 chars

puts gets.split.map(&:to_i).select{|x| x>0}.inject(&:+)

--53 chars

seems going the old fashioned way is shorter code,
yup wanted for x>0 and between this was a problem to see on different 
languages
python was around 26 , so i was thinking if i could do less than that on 
ruby...

puts eval(gets.gsub(/-\d+|[^0-9]+/, '+')<<'+0')

Am 08.03.2010 um 22:10 schrieb Prasanth Ravi:

Florian Aßmann wrote:
> puts eval(gets.gsub(/-\d+|[^0-9]+/, '+')<<'+0')
> 
> Am 08.03.2010 um 22:10 schrieb Prasanth Ravi:

irb(main):001:0> puts eval(gets.gsub(/-\d+|[^0-9]+/, '+')<<'+0')
1 2 3 4
10
=> nil
irb(main):002:0> puts eval(gets.gsub(/-\d+|[^0-9]+/, '+')<<'+0')
1 -2 3 4
10
=> nil
irb(main):003:0> puts eval(gets.gsub(/-\d+|[^0-9]+/, '+')<<'+0')
1 -2 -34 5
42
=> nil
irb(main):004:0> puts eval(gets.gsub(/-\d+|[^0-9]+/, '+')<<'+0')
-234
0
=> nil
irb(main):005:0> puts eval(gets.gsub(/-\d+|[^0-9]+/, '+')<<'+0')
-2 -3 -4
7
=> nil
irb(main):006:0> puts eval(gets.gsub(/-\d+|[^0-9]+/, '+')<<'0')
1 2 3 43
49
=> nil
irb(main):007:0> puts eval(gets.gsub(/-\d+|[^0-9]+/, '+')<<'0')
1 -2 3 4
10
=> nil


it's shorter code(45 chars) but i think negative numbers also get added 
to result( or not- check case 5), seems can't get below 35

Prasanth Ravi wrote:
> tx for the reply, i originally used
> y=0
> gets.split.each{ |x|
>   z=x.to_i
>   y+=z if z>0
> }
> print y

You can save a char by replacing

y=0;s.split.each{|x|z=x.to_i;y+=z if z>0}

with

y=0;s.split.each{|x|y+=x.to_i if /-/!~x}

but this is even shorter

y=0;s.scan(/ \d+|^\d+/){|x|y+=x.to_i}

Ruby 1.9: 34 characters

eval(gets.scan(/(?:^| )(\d+)/)*?+)

Aaron out

Aaron D. Gifford wrote:
> Ruby 1.9: 34 characters
> 
> eval(gets.scan(/(?:^| )(\d+)/)*?+)
> 
> Aaron out

edit:
y=0
s=""
s.scan(/ \d+|^\d+/){|x|y+=x.to_i}
puts y

i put puts y so i can do it in a script file instead of irb and removed 
semicolons as ';' counts as a char,

38 char-w/o puts y
43 chars-with puts y

this is the shortest i have seen w/o getting into an infinite loop :D,ty

Aaron D. Gifford wrote:
> Ruby 1.9: 34 characters
> 
> eval(gets.scan(/(?:^| )(\d+)/)*?+)
> 
> Aaron out

tx aaron this is by far the shortest code ive seen...

On Mon, Mar 8, 2010 at 10:38 PM, Prasanth Ravi <dare.take@gmail.com> 
wrote:
>>> puts gets.split(' ').inject(0){|sum,x| x.to_i>0?sum+x.to_i : sum}
>> Cheers
>> R.
>
> puts gets.split.map(&:to_i).select{|x| x>0}.inject(&:+)
>
> --53 chars
>

I feel that your code has less characters and mine is shorter :)
R.

Robert Dober wrote:
> On Mon, Mar 8, 2010 at 10:38 PM, Prasanth Ravi <dare.take@gmail.com> 
> wrote:
>>>> puts gets.split(' ').inject(0){|sum,x| x.to_i>0?sum+x.to_i : sum}
>>> Cheers
>>> R.
>>
>> puts gets.split.map(&:to_i).select{|x| x>0}.inject(&:+)
>>
>> --53 chars
>>
> 
> I feel that your code has less characters and mine is shorter :)
> R.

yea your's is definitely better(it's more readable), but the problem 
measure the code by character count :D

Prasanth Ravi wrote:
> Aaron D. Gifford wrote:
>> Ruby 1.9: 34 characters
>> 
>> eval(gets.scan(/(?:^| )(\d+)/)*?+)
>> 
>> Aaron out
> 
> tx aaron this is by far the shortest code ive seen...

A variation:

p eval gets.split(/ |-\d+/)*?+

Siep

Siep Korteling wrote:
> Prasanth Ravi wrote:
>> Aaron D. Gifford wrote:
>>> Ruby 1.9: 34 characters
>>> 
>>> eval(gets.scan(/(?:^| )(\d+)/)*?+)
>>> 
>>> Aaron out
>> 
>> tx aaron this is by far the shortest code ive seen...
> 
> A variation:
> 
> p eval gets.split(/ |-\d+/)*?+
> 
> Siep

irb(main):003:0> p eval gets.split(/ |-\d+/)*?+
1 -2 -3 -5
SyntaxError: (eval):1: syntax error, unexpected $end
  from (irb):3:in `eval'
  from (irb):3
  from /usr/bin/irb1.9:12:in `<main>'
irb(main):004:0> p eval gets.split(/ |-\d+/)*?+
1 2 3 4 5
15
=> 15
irb(main):005:0>

i got this output maybe some env change?

Prasanth Ravi wrote:
> Siep Korteling wrote:

> i got this output maybe some env change?

No, it just doesn't work with a trailing negative number. One more try:

p eval gets.split(/ |-\d+/)*'+0'

Siep

Siep Korteling wrote:
> Prasanth Ravi wrote:
>> Siep Korteling wrote:
> 
>> i got this output maybe some env change?
> 
> No, it just doesn't work with a trailing negative number. One more try:
> 
> p eval gets.split(/ |-\d+/)*'+0'
> 
> Siep

yea it works perfectly...
29 chars...
we went from 53 to 29 .. nice tx man..
and pythons was 27...
pretty nice.. gues it's my final solution.. tx again for all who post a 
reply...

interesting...

ree-1.8.7-2010.01 > puts eval(gets.gsub(/(?:-\d|[^0-9])+/, '+')<<'+0')
1 2 3 -4
6
 => nil
ree-1.8.7-2010.01 > puts eval(gets.gsub(/(?:-\d|[^0-9])+/, '+')<<'+0')
1 -2 3 4
8
 => nil

ol' ruby?

Am 09.03.2010 um 04:39 schrieb Prasanth Ravi:

Florian Aßmann wrote:
> interesting...
> 
> ree-1.8.7-2010.01 > puts eval(gets.gsub(/(?:-\d|[^0-9])+/, '+')<<'+0')
> 1 2 3 -4
> 6
>  => nil
> ree-1.8.7-2010.01 > puts eval(gets.gsub(/(?:-\d|[^0-9])+/, '+')<<'+0')
> 1 -2 3 4
> 8
>  => nil
> 
> ol' ruby?
> 
> Am 09.03.2010 um 04:39 schrieb Prasanth Ravi:

irb(main):010:0> puts eval(gets.gsub(/(?:-\d|[^0-9])+/, '+')<<'+0')
3 4 -5
7
=> nil
irb(main):011:0> puts eval(gets.gsub(/(?:-\d|[^0-9])+/, '+')<<'+0')
-56
6
=> nil

was it -(56) or -5 & 6 ? :D

On Wed, Mar 10, 2010 at 9:07 AM, Prasanth Ravi <dare.take@gmail.com> 
wrote:
>>  => nil
> -56
> 6
> => nil
>
> was it -(56) or -5 & 6 ? :D
> --
> Posted via http://www.ruby-forum.com/.
>
>
1 -2 8 is nice too ;)
Even spec your golfs !!!