# Detect rotated strings

Output Yes if one string is a rotated version of the other.
Otherwise output No

Testcases

Input

CodeGolf GolfCode

Output

Yes

Input

stackexchange changestackex

Output

Yes

Input

stackexchange changestack

Output

No

Input

Hello World

Output

No
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 So (abcdefAB, ABabcdef) is a "YES"? – Eelvex Mar 9 '11 at 12:06 Should it really be a rotation or is a combination fine too? eg. what will Stackexchange Stackchangeex return? – jpjacobs Mar 9 '11 at 12:08 @Eelvex, yes. @jpjacobs, It would return No. The rotation is a shift, like those LED scrolling signs – gnibbler♦ Mar 9 '11 at 12:19 Are the strings always whitespace-free and separated by whitespace? – Joey Mar 9 '11 at 15:20 More specifically, what characters are allowed in those strings? – Joey Mar 9 '11 at 15:48

## APL (28)

Takes input on two lines.

'No' 'Yes'[1+(⊂⍞)∊⌽∘A¨⍳⍴A←⍞]

Explanation:

• A←⍞: read a line of input and store it in A
• ⌽∘A¨⍳⍴A: Rotate A by x, for each x in [1..length A]. Gives a list, i.e. estT stTe tTes Test
• (⊂⍞)∊: read another line of input, and see if it is in this list.
• 1+: add one to this, giving 1 if the strings were not rotated and 2 if they were
• 'No' 'Yes'[...]: Select either the first or second element from the list 'No' 'Yes' depending on whether the strings were rotated or not.
• This value is output automatically.
-

## Ruby 49 41

a,b=\$*;puts (a*2).sub(b,'')==a ?:yes: :no

Edit: replaced gets.split by \$*

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 That's an ingenious idea. – Joey Mar 9 '11 at 21:40 Very clever. :) – st0le Mar 18 '11 at 4:56

## Python-70 bytes

a,b=raw_input().split()
print ['No','Yes'][a in b*2and len(a)==len(b)]

Testing ...

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+1 Nice, selecting the result from an array is clever! :-) – Tom Wijsman Mar 9 '11 at 15:24
The question states you should read two strings from stdin, which this solution does not. – Ventero Mar 9 '11 at 15:36
@Ventero:Fixed. – Quixotic Mar 9 '11 at 18:43

## J, 47

y=:>2{ARGV
(>1{ARGV e.1|.^:(i.#y)y){'No',:'Yes'
-
 Why the two J answers? – J B Mar 9 '11 at 19:49 @JB: because this one uses the buildin rotate. Both answers su^H^H are not so good btw. There is a lot of room for golfing. – Eelvex Mar 9 '11 at 19:57 why the other one, then, I'm tempted to ask? :-) – J B Mar 9 '11 at 20:06 @JB: because I thought this one is barely legal ( :p ) [ while the other one extends nicely to lisp. ] – Eelvex Mar 9 '11 at 20:13 errr... the other one seems to read input from the command-line as well – J B Mar 9 '11 at 20:15

Python 70 Characters

a,b=raw_input().split()
print'YNeos'[len(a)<>len(b)or a not in 2*b::2]

Thanks to gnibbler for the slice trick.

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Same problem as the GolfScript solution: If you input nn nfn, you get Yes, which is wrong. – Tom Wijsman Mar 9 '11 at 14:28
@TomWij Thanks for finding the bug. Corrected. Should work now. – fR0DDY Mar 9 '11 at 15:14
You can replace <> by - as that will also result in 0 if they are of equal length. – Tom Wijsman Mar 9 '11 at 15:28
But what if they are not of equal length? Then it doesn't work so well :-) – hallvabo Mar 13 '11 at 13:38
@hallvabo then the strings are not rotated version of each other. – fR0DDY Mar 13 '11 at 13:52

According to the spec (same string lengths):

### Perl, 42 43 chars

\$.=pop;\$_=(pop)x2;print+(qw'yes no')[!/\$./]

If different sized strings are allowed, the solution would be:

### Perl, 47 chars

\$.=(pop)x8;\$_=(pop)x9;print+(qw'yes no')[!/\$./]

rbo

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Same problem as the GolfScript solution: If you input nn nfn, you get Yes, which is wrong. – Tom Wijsman Mar 9 '11 at 14:17
seems to be ok (I missed the'!' in the first version) "nn nfn" => no "CodeGolf GolfCode" => yes – rubber boots Mar 9 '11 at 14:22

## J, 57

{&('No';'Yes')@-:/@:((/:~@(|."0 _~i.&\$))&.>)&.(;:&stdin)_

Sample use:

\$ echo -n CodeGolf GolfCode | jconsole rotate.ijs
Yes
\$ echo -n stackexchange changestackex | jconsole rotate.ijs
Yes
\$ echo -n stackexchange changestack | jconsole rotate.ijs
No
\$ echo -n Hello World | jconsole rotate.ijs
No
-

## Golfscript, 31

' '/:)~,\,=)~.+\/,(&'Yes''No'if

This one check length first, so it should work as expected.

-

## JavaScript, 51

function f(a,b)a&&(a+a).replace(b,"")==a?"Yes":"No"

JavaScript doesn't have a canonical host, so this answer is written as a function of two arguments. The score goes up to 60 if we disallow JS 1.7 features (expression closures).

In the SpiderMonkey shell this would be (for a score of 71):

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## J, 84

y=:(>1{ARGV),:(>2{ARGV)
((0{y)e.(y&((]\$0{[),(]-~[:}.[:\$[)\$1{[)/.i.}.\$y)){'No',:'Yes'
-

JavaScript (120 chars)

function f(a,b) {for (i=0,A=a.split("");A.join("")!=b&&i++<a.length;A.push(A.shift()));return A.join("")==b?'Yes':'No';}

Output:

f('CodeGolf','GolfCode'); //Yes
f('stackexchange','changestackex'); //Yes
f('stackexchange','changestack'); //No
f('Hello','World'); //No
f('nn','nBn'); //No
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## Ruby, 58 (62) characters

a,b=gets.split;\$><<(a.size==b.size&&/#{a}/=~b*2?:Yes: :No)

This solution assumes the input contains only alphanumeric characters (actually everything that doesn't have a special meaning inside a regular expression is ok).

A solution that doesn't have this constraint is 4 characters longer

a,b=gets.split;\$><<(a.size==b.size&&(b*2).index(a)?:Yes: :No)
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## Windows PowerShell, 76

\$a,\$b=-split\$input
('No','Yes')[+!(\$a.length-\$b.length)*"\$b\$b".contains(\$a)]
-

## Python, 71

a,b=raw_input().split()
print'Yes'if a in b*2and len(a)==len(b)else'No'
-
 Same problem as the GolfScript solution: If you input nn nfn, you get Yes, which is wrong. – Timwi Mar 9 '11 at 14:08 Problem has been solved, remains low... :-) – Tom Wijsman Mar 9 '11 at 14:17 Doesn't read from stdin as specified. – Wooble Mar 9 '11 at 16:57 Now it does... :-) – Tom Wijsman Mar 9 '11 at 18:59

## PHP, 61

<?echo preg_match('/^(.+)(.*) \\2\\1\$/',fgets(STDIN))?Yes:No;
-

## Ruby, 41

puts gets =~ /^(.+)(.*) \2\1\$/ ?:Yes: :No
-
 Doesn't print anything, results in ':No' for input 'aaa aaa' (on my machine). The regexp approach could be a good idea though. – steenslag Mar 25 '11 at 0:43 Fix to actually print and input from stdin instead of args: puts gets =~ /^(.+)(.*) \2\1\$/ ?:Yes: :No - ups it to 41 chars. – Nemo157 Mar 25 '11 at 4:12 Thanks, I'll make the change @Nemo157 . – Daniel Apr 11 '11 at 20:15

g x y@(t:r)(z:w)|x==y="Yes"|1>0=g x(r++[t])w
g _ _[]="No"
f(x:y:_)=g x y y
main=interact\$f.words
-

Fixed to say Yes/No and improved (91 chars)

import List;f[a,b]|a`elem`[x++y|x<-tails b|y<-inits b]="Yes";f _="No";main=interact\$f.words

original Haskell (92 chars) that says True/False

import Data.List;f(a:b:_)=any(a==)\$zipWith(++)(tails b)(inits b);main=interact(show.f.words)
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 You can save a few characters with import List and also by using \$ instead of parens around the argument to interact. But your program outputs True and False instead of the required Yes and No, so that might take a few extra chars to fix. – jloy Apr 15 '11 at 3:38 Thanks for the constructive criticism, jloy – Chris Kuklewicz Apr 15 '11 at 14:20

# Q (50 43 chars)

{`No`Yes x in((!)(#)y)rotate\:y}." "vs(0:)0
-

Scala 78

print(b(0).size==b(1).size&&(b(0)+b(0)contains b(1)))

It's a shame about the size check, without it the count drops to 54

print(a(0)+a(0)contains a(1))
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 """val b=readLine split " " print(b(0).sorted==b(1).sorted)""".length yields 56 – user unknown Jun 1 '12 at 3:49

Lua 115 chars

a,b=io.read():match"(%w+) (%w+)"c=b repeat c=c:sub(2,-1)..c:sub(1,1) s=s or a==c until b==c print(s and"Yes"or"No")
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## C program - 146

char b[99],c[99],*p,*q;main(n){q=(p=b+(n=strlen(gets(c))))+n;sprintf(b,"%s%s"
,c,c);for(gets(c);p>b&&strcmp(p,c);--p,*--q=0);puts(p>b?"Yes":"No");}
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## PHP, 82 characters

<?\$s=split(" ",fgets(STDIN));echo str_replace(\$s[1],"",\$s[0].\$s[0])==\$s[0]?Yes:No;
-

perl, 123 chars

@s1=split(//,shift);
\$s2=shift;
\$i=0;
while(\$i<=@s1){
if(join("",@s1) eq \$s2){die "yes";}
unshift @s1,pop @s1;
\$i++;
}
die "no";
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## Ruby, 30 37

gets
puts~/^(.+)(.*) \2\1\$/?:Yes: :No

A version that prints "true" and "false" instead of "yes" and "no":

gets
p !! ~/^(.+)(.*) \2\1\$/

Both of these work with different-length strings (unlike the old one)

-
 Does work if the two strings have the same length, but fails on input like 'golfcode golf'. – steenslag Mar 25 '11 at 0:37

## Python 2, 86 Characters

a,b=raw_input().split()
print"Yes"if any(a==b[n:]+b[:n]for n in range(len(a)))else"No"
-

## Perl (just a quick fix)

A fix to rubber boots' solution, being a new user that I am I can't comment yet so I'll just post a new answer.

As the mentioned method uses a regular expression constructed from user input, it is possible to perform a small regex injection, as follows:

> perl -le '\$.=pop;\$_=(pop)x2;print+(qw/yes no/)[!/\$./]' anything '.*'
yes

The fix is to use \Q (known also as quotemeta):

> perl -le '\$.=pop;\$_=(pop)x2;print+(qw/yes no/)[!/\Q\$./]' anything '.*'
no

The code itself could be further shortened using 'say' but this is left as an exercise to the reader :)

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 Furthermore, instead of print+(qw/yes no/)[ you can probably write print qw(yes no)[ which is two characters shorter. – Timwi Apr 12 '11 at 22:58

# Clojure, 95

The function rotated? simply tests one string against all possible rotations of the other. Brute force.

(defn rotated?
[a b]
(let[l (count a)
b (seq b)]
(->> a cycle (partition l 1) (take l) (some #{b}))))

I personally don't care where the input strings come from, but if it has to be stdin...

(apply rotated? (.split (read-line) " "))

This would add 38 to character count, if strings were whitespace separated.

This would add 32 to character count, if strings were newline separated. The function rotated? works with any characters in the strings.

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# Bash, 706559 55 characters

new approach:

read a b;c=\$a\$a;[[ \${c/\$b/} == \$a ]]&&echo yes||echo no
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solution 2 fails on echo ofofo fofof | bash rotated.sh - doesn't it? Else I would remove even more WS: read a b[[ \$a\$a =~ \$b&&\${#a}-eq\${#b} ]]&& echo yes||echo no. I had a very similar idea, and think it works. – user unknown May 30 '12 at 6:21
You're right, more ws can be removed, and the paratheses! Need a ; after the read tho. – Daniero May 30 '12 at 14:16
@userunknown - hah, got'cha ;) – Daniero May 31 '12 at 23:13
You can remove a blank before and one behind ==. – user unknown Jun 1 '12 at 3:41
I tried, but then it always return 'yes'. – Daniero Jun 7 '12 at 14:46
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