Right-align text

Question

Your job is to take a string input and a number and align the string to the right, making the width of the text the number. When a line is too long, break it and put the rest on the next line, repeating until it's not necessary. If a line is shorter than the width, then pad it with spaces. Multiple newlines can occur, and should be treated like any other single character.

For example, the string

Programming
Puzzles
&
Code
Golf

and the number 5 would produce:

Progr
ammin
    g
Puzzl
   es
    &
 Code
 Golf

Whereas the same string and the number 10 would produce:

Programmin
         g
   Puzzles
         &
      Code
      Golf

The string

a

b

and the number 5 would produce:

    a
      <-- note the 5 spaces
    b

Shortest code wins!

The text says “Break the lines when necessary [...]”, but your examples suggest that you break after every word, even when it would fit. Please clarify: do we place each word on a new line, or do we implement an actual word-wrapping algorithm? — Timwi, Sep 24, 2015 at 0:39
Can there be spaces in the middle of an input line, e.g. Programming Puzzles\n&\nCode Golf? — Sp3000, Sep 24, 2015 at 2:04
@Timwi: The example has one word per line. It would have been better to include some multi-word lines to make it clear that space within a line isn't special. (i.e. there are only newlines, and non-newlines.) — Peter Cordes, Sep 24, 2015 at 8:58

Community · Accepted Answer · 2020-06-17 09:04:33Z

10

Python 2, 84

s,n=input()
for w in s.split('\n'):
 w=w or' '
 while w:print w[:n].rjust(n);w=w[n:]

Takes as input a string with newlines and a number, and prints the result. For each line in the input, takes and prints n chars at a time, using the built-in rjust to pad the left with spaces before printing.

I fixed the empty line case with the hack w=w or' '. There's probably a better method but I'm not going to think much about it.

edited Jun 17, 2020 at 9:04

CommunityBot

1

answered Sep 24, 2015 at 1:48

xnor

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isaacg · Accepted Answer · 2015-09-24 05:53:43Z

8

Pyth, 14 bytes

jm.[\ QdscRQ.z

Demonstration

Uses Pyth's pad operator.

answered Sep 24, 2015 at 5:53

isaacg

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Dennis · Accepted Answer · 2015-09-25 03:57:05Z

CJam, 21 bytes

li_qN/Sfe|f/ff{\Se[N}

Thanks to @Sp3000 for golfing off 1 byte and paving the way for 3 more.

Try it online in the CJam interpreter.

How it works

li                     Read an integer L from the first line of input.
  _                    Push a copy.
   qN/                 Split the remaining input at linefeeds.
      Sfe|             Map `OR " "'; the replaces empty lines with a space.
          f/           Split each line into chunks of length L.
            ff{     }  For each chunk, push L and the chunk; then:
               \         Swap L with the chunk.
                Se[      Left-pad the chunk to length L by prepending " ".
                   N     Push a linefeed.

Community · Accepted Answer · 2020-06-17 09:04:33Z

5

Pyth, 16

jm>Q+*\ QdscRQ.z

Try it online here

Explanation

jm>Q+*\ QdscRQ.z             : Q is the number on the first line, .z takes the rest
           cRQ.z             : chop each line of .z into chunks of Q characters
 m        s                  : remove nested lists and map over the result
    +*\ Qd                   : add Q spaces to each line d
  >Q                         : take the last Q characters of that result
j                            : join results on newlines

edited Jun 17, 2020 at 9:04

CommunityBot

1

answered Sep 24, 2015 at 2:20

FryAmTheEggman

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ThisSuitIsBlackNot · Accepted Answer · 2015-09-24 20:43:02Z

Perl, 39 bytes

perl -ni5 -e 's!^$|.{1,$^I}!printf"%${^I}s
",$&!ge'

36 bytes + 3 bytes for -ni. The wrap width is passed as the argument to -i.

Handles blank lines properly by padding them with spaces:

$ echo -e "Programming\nPuzzles\n\n&\n\nCode\nGolf" | perl -ni5 -e 's!^$|.{1,$^I}!printf"%${^I}s
",$&!ge'
Progr
ammin
    g
Puzzl
   es

    &

 Code
 Golf

How it works

This solution uses the substitution operator to loop through the input, saving a byte over the equivalent for loop. The real trick, though, is in the regex on the LHS of the substitution:

^$|.{1,$^I}

With the global modifier, this will match $^I characters at a time; when there are less than $^I characters remaining in the string, it will match everything to the end. The alternation with ^$ is required to handle blank lines. For example:

$ echo -e "foo\n\nbar" | perl -ni2 -E 'say "<$_>" for /^$|.{1,$^I}/g'
<fo>
<o>
<>
<ba>
<r>

The RHS of the substitution simply uses printf to left-pad the matched chunk with spaces.

@DomHastings I learned that trick from chilemagic, who mentioned it in a comment on another challenge. — ThisSuitIsBlackNot, Sep 24, 2015 at 21:11

DankMemes · Accepted Answer · 2015-09-24 02:11:49Z

Javascript (ES6), 107

I wish JS had a built in pad function. Oh well.

(a,b)=>a.replace(eval(`/(.{${b}})(?!\\n)/g`),`$1
`).split`
`.map(c=>(Array(b).join` `+c).slice(-b)).join`
`

Explanation:

(a, b)=>

  // searches for sequences of characters longer than b without a newline after them and
  // adds a newline after every b characters of the sequence
  a.replace(eval(`/(.{${b}})(?!\\n)/g`), '$1\n')
    .split('\n')
    .map(c=>

      // prepends b spaces to each string then slices it from the right down to length b
      ( Array(b).join(' ') + c ).slice(-b)

    ).join('\n')

Alex A. · Accepted Answer · 2015-09-24 04:01:59Z

3

Julia, 126 bytes

f(s,n)=for i=split(s,"\n") while length(i)>0 println(lpad(i[1:min(n,end)],n));length(i)<n?break:(i=i[min(n+1,end):end])end;end

Ungolfed:

function f(s::String, n::Int)
    for i in split(s, "\n")
        while length(i) > 0
            println(lpad(i[1:min(n,end)], n))
            length(i) < n ? break : (i = i[min(n+1,end):end])
        end
    end
end

answered Sep 24, 2015 at 4:01

Alex A.

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Peter Cordes · Accepted Answer · 2015-09-24 06:46:02Z

2

Bash, 62, 61+feature, 59

Shorter if N can be set by the caller, instead of having to read it as the first line of input.

# width as a function arg: 59 chars
f()while read -rn$1 r;do [[ $r ]]&&printf %$1s\\n "$r";done
# width on stdin: 64 chars  (not updated with later suggestions&ideas)
read N;while read -rn$N r;do [[ $r ]]&&printf %$N's\n' "$r";done

This fails to handle empty lines in the input. Otherwise, this doesn't subject the input data to word-splitting, pathname expansion, or otherwise treat it as more than just raw data.

read -n$N saves one character, but lets read munge \.

The [[ $r ]]&& is needed because read -n4 can't lookahead to see that the next char is a newline. So it sets r to a 4-char string, and the next read produces a zero-char empty string. Filtering these false newlines without filtering real newlines would require tracking state: whether the previous line was max-length or not. Either more code or a totally different approach would be needed.

[[ $r ]] is shorter than [ -n "$r" ] which is needed to avoid errors if the line starts with -z foo, or is * or something, if you used [ $r ].

Justication happens with the standard printf "%4s" format string.

Test with

f()(while read -rn$1 r;do [[ $r ]]&&printf %$1s\\n "$r";done); (echo 4; echo -e "*\n\\"; cat /tmp/lines) | f 4

edited Sep 24, 2015 at 6:46

answered Sep 24, 2015 at 6:26

Peter Cordes

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\$\begingroup\$ 1. I'd include -r in the byte count. 2. f()(while ... done) is a bit shorter. \$\endgroup\$
– Dennis
Sep 24, 2015 at 6:36
\$\begingroup\$ @Dennis: Without [[ $r ]]&&, if N=4, an input line of length 4 will produce a blank output line where there wasn't one before. Because read returns a string of 4 chars, then sees a newline on the next call and returns right away. Also, thanks for the () tip. I didn't know you could define fns that way. \$\endgroup\$
– Peter Cordes
Sep 24, 2015 at 6:37
\$\begingroup\$ I recommend reading Tips for golfing in Bash. It's a great resource. \$\endgroup\$
– Dennis
Sep 24, 2015 at 6:39
\$\begingroup\$ Actually, since while is already compound, you don't even need the parentheses: f()while ... done \$\endgroup\$
– Dennis
Sep 24, 2015 at 6:42
\$\begingroup\$ @Dennis: wow, haxx. Thanks for the link. A couple of those things were new to me, and I fixed a couple things in another answer :) I don't normally golf, but >15 years of being a command-line junkie has taught me a thing or two :) \$\endgroup\$
– Peter Cordes
Sep 24, 2015 at 7:18

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nimi · Accepted Answer · 2015-09-24 16:35:57Z

Haskell, 108 bytes

import Data.List.Split
k[]=[""]
k x=x
f n=unlines.(map(\l->([1..n-length l]>>" ")++l).k.chunksOf n=<<).lines

Usage example:

*Main> putStr $ f 5 "a\n\nb\ncd\nMatamorphosis"
    a

    b
   cd
Matam
orpho
  sis

How it works

                              .lines   -- split input string at newlines
                           =<<         -- for every line
                  chunksOf n           --    split into chunks of length n
                k                      --    fix empty lines
    map                                --    for every chunk
        \l->([1..n-length l]>>" "      --      make a string of missing spaces
                        ++l            --      and append the chunk
unlines                                -- join padded chunks with newlines in-between

Peter Cordes · Accepted Answer · 2015-09-24 08:53:12Z

GNU awk + bash, 70

f()(awk -vFPAT=.\{,$1} '{for(i=0;i++<NF;){printf "%'$1's\n",$i}}/^$/')

Using bash to slot the count into the awk program is prob. smaller than reading it with a NR==1{N=$0} block.

Read a line at a time. Split into at-most-4 character chunks, using FPAT. (matches the fields, rather than the separators. GNU extension.) printf each field separately. (Default ORS = \n).

The /^$/ rule is there to print empty lines, which have NF=0 and thus don't print at all in the other block. So unlike my pure-bash solution, this actually works in the general case.

Semi-unrelated, but my idea so far for perl is 112 chars for just the perl code:

(echo 4; echo -e 'foo\nbar'; echo -e "*\n\\"; echo '~$(true)'; cat /tmp/lines) |  # test input
perl -e '$N=<>;$/=\1;print "$N\n"; while(<>){if(/\n/ or length($l)>=$N){printf("%$4s\n",$l);$l=/\n/?"":$_;}else{$l.=$_;}}'

This eats one of the newlines, and is way too long. $/=\1 reads a byte at a time. We append to $l. Probably a line-at-a-time with fixed-width split approach would be shorter.

Community · Accepted Answer · 2020-06-17 09:04:33Z

1

Bash + GNU utils, 41

fold -$1|sed ":;s/^.\{,$[$1-1]\}\$/ &/;t"

String is input via STDIN, width is input by command-line arg:

ubuntu@ubuntu:~$ echo 'Programming
Puzzles
&
Code
Golf'|./ralign.sh 10
Programmin
         g
   Puzzles
         &
      Code
      Golf
ubuntu@ubuntu:~$

edited Jun 17, 2020 at 9:04

CommunityBot

1

answered Sep 24, 2015 at 17:47

Digital Trauma

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2 revs · Accepted Answer · 2015-09-25 01:10:31Z

Python 2, 151 bytes

s,n=input();N='\n'
for w in[i.lstrip()if i.replace(' ','').isalpha()else i for i in s.replace(N,'\n ').split(N)]:
 while w:print w[:n].rjust(n);w=w[n:]

This is a adaptation of @xnor's answer above, as his does not properly handle newlines.

The for loop was changed from:

for w in s.split('\n'):

to:

for w in[i.lstrip()if i.replace(' ','').isalpha()else i for i in s.replace(N,'\n ').split(N)]:

Example

$ python main.py
"Programming\n\n\nPuzzles\n\n&\n\nCode\nGolf", 5
Progr
ammin
    g


Puzzl
   es

    &

 Code
 Golf

Carl Walsh · Accepted Answer · 2015-09-25 07:15:04Z

C#, 143 bytes

(s,n)=>Join("\n",s.Split('\n').SelectMany(l=>(l.Any()?l:" ").Select((c,i)=>new{c,i}).GroupBy(o=>o.i/n,o=>o.c).Select(g=>Concat(g).PadLeft(n))))

Linq lets you make pretty gnarly expressions. GroupBy is useful here, but it's a shame they couldn't create function overloads taking the index.

Assign the lambda to a Func<string, int, string> to run it

Less golfed:

Func<string, int, string> Align = (s, n) => Join("\n", 
    s.Split('\n')
     .SelectMany(l => (l.Any() ? l : " ")
         .Select((c, i) => new { c, i })
         .GroupBy(o => o.i / n, o => o.c)
         .Select(g => Concat(g).PadLeft(n))));

dbramwell · Accepted Answer · 2015-09-25 13:10:48Z

1

Groovy, 63 bytes

Returns the correctly alligned string. Didn't know there was a padLeft (and padRight, padCenter) function until now.

f={s,n->s.split("(?<=\\G.{$n})|\n")*.padLeft(n," ").join("\n")}

edited Sep 25, 2015 at 13:10

answered Sep 25, 2015 at 12:36

dbramwell

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wolfhammer · Accepted Answer · 2015-09-25 13:46:39Z

1

JavaScript 174 136

function R(s,x){return s.replace(new RegExp(".{"+x+"}","g"),"$&\n").replace(/[^\n]*/g,function(m){
while(m.length<x)m=" "+m;return m;})}

edited Sep 25, 2015 at 13:46

answered Sep 25, 2015 at 13:33

wolfhammer

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Roland Tepp · Accepted Answer · 2015-09-25 14:21:01Z

1

Ceylon, 107

String w(String s,Integer n)=>"\n".join{for(l in s.lines)for(p in l.partition(n))String(p).padLeading(n)};

answered Sep 25, 2015 at 14:21

Roland Tepp

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Luis Mendo · Accepted Answer · 2015-09-25 22:44:08Z

Matlab, 99 bytes

Thanks to @beaker for removing 6 bytes!

Using and anonymous function:

@(s,k)fliplr(char(cellfun(@fliplr,strsplit(regexprep(s,sprintf('\\S{%i}',k),'$0\n'),'\n'),'un',0)))

Define the function and use ans to call it:

>> @(s,k)fliplr(char(cellfun(@fliplr,strsplit(regexprep(s,sprintf('\\S{%i}',k),'$0\n'),'\n'),'un',0)))

ans =

@(s,k)fliplr(char(cellfun(@fliplr,strsplit(regexprep(s,sprintf('\\S{%i}',k),'$0\n'),'\n'),'un',0)))

>> ans(['Programming' 10 'Puzzles' 10 '&' 10 'Code' 10 'Golf'], 5) %% 10 is line feed

ans =

Progr
ammin
    g
Puzzl
   es
    &
 Code
 Golf

mroman · Accepted Answer · 2015-10-22 14:23:33Z

1

Burlesque, 28 Bytes

Same as the version below, but treats line 1 as the number and the other lines as the string.

lng_riPpun{pPco{pP' lp}mu}Wl

Usage as in:

$ cat input.txt | blsq --stdin "lng_riPpun{pPco{pP' lp}mu}Wl"
Progr
ammin
    g
Puzzl
   es
    &
 Code
 Golf

Old Version (16 bytes):

{5co{5' lp}mu}Wl

Example:

blsq ) "Programming\nPuzzles\n&\nCode\nGolf"{5co{5' lp}mu}Wl
Progr
ammin
    g
Puzzl
   es
    &
 Code
 Golf

edited Oct 22, 2015 at 14:23

answered Sep 25, 2015 at 11:54

mroman

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Stack Exchange Network

Right-align text

18 Answers 18

Python 2, 84

Pyth, 14 bytes

CJam, 21 bytes

How it works

Pyth, 16

Explanation

Perl, 39 bytes

How it works

Javascript (ES6), 107

Julia, 126 bytes

Bash, 62, 61+feature, 59

Haskell, 108 bytes

GNU awk + bash, 70

Bash + GNU utils, 41

Python 2, 151 bytes

Example

C#, 143 bytes

Groovy, 63 bytes

JavaScript 174 136

Ceylon, 107

Matlab, 99 bytes

Burlesque, 28 Bytes

Your Answer

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code-golf
string
or ask your own question.

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Right-align text

18 Answers 18

Python 2, 84

Pyth, 14 bytes

CJam, 21 bytes

How it works

Pyth, 16

Explanation

Perl, 39 bytes

How it works

Javascript (ES6), 107

Julia, 126 bytes

Bash, 62, 61+feature, 59

Haskell, 108 bytes

GNU awk + bash, 70

Bash + GNU utils, 41

Python 2, 151 bytes

Example

C#, 143 bytes

Groovy, 63 bytes

JavaScript 174 136

Ceylon, 107

Matlab, 99 bytes

Burlesque, 28 Bytes

Your Answer

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Not the answer you're looking for? Browse other questions tagged
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