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Question

Task

Given a String as input, your task is to output 42 only if the input String happens to be exactly the following :

abbcccddddeeeeeffffffggggggghhhhhhhhiiiiiiiiijjjjjjjjjjkkkkkkkkkkkllllllllllllmmmmmmmmmmmmmnnnnnnnnnnnnnnoooooooooooooooppppppppppppppppqqqqqqqqqqqqqqqqqrrrrrrrrrrrrrrrrrrsssssssssssssssssssttttttttttttttttttttuuuuuuuuuuuuuuuuuuuuuvvvvvvvvvvvvvvvvvvvvvvwwwwwwwwwwwwwwwwwwwwwwwxxxxxxxxxxxxxxxxxxxxxxxxyyyyyyyyyyyyyyyyyyyyyyyyyzzzzzzzzzzzzzzzzzzzzzzzzzz

It may output any other value, produce an error or not output at all, if the input does not equal the aforementioned String.

---

Winning Criterion

This is code-golf, so the shortest code in bytes wins!

Answer 1

Haskell, 45 51 bytes

f x|x==zip[1..]['a'..'z']>>=uncurry replicate->"42"

zip [1..] ['a'..'z'] produces the list [(1,'a'), (2,'b'), ...].

uncurry replicate has the type (Int, a) -> [a], and uncurry replicate (n, v) produces a list of n copies of v.

>>= applies uncurry replicate to the zipped list, and concatenates the results.

Finally, that string compared to the argument and returns "42" if it is equal, or crashes.

(edited b/c I'm dumb and didn't notice the return requirement)

Answer 2

Pylongolf2, 21 bytes

con1968701440=?42~¿

Explanations:

con1968701440=?42~¿
c                   read input
 on                 hash it and then convert into integer
   1968701440       push the (aaa.zz) thing (but hashed) into the stack
             =      compare them
              ?     if true,
               42~  output 42
                  ¿ end if statement.

That last inverted question mark messed me up by 2 bytes :|

Answer 3

SmileBASIC, 58 bytes

DEF F S
FOR I=1TO 26C$=C$+CHR$(I+64)*I
NEXT?42OR C$!=S
END

I had to make it a function since the maximum INPUT length is 128 characters.

Answer 4

R, 74 bytes

g=function(x){if(x==paste(rep(rep(letters[1:26]),(1:26)),collapse=""))42}

Answer 5

Axiom, 141 bytes

f(x:String):NNI==(c:=96;i:=0;k:=1;repeat(c:=c+1;i:=i+1;for j in 1..i repeat(k>#x or ord(x.k)~=c=>return 0;k:=k+1);c=122=>break);k=#x+1=>42;0)

ungolf

--It would return 42 if the string in input it is as string above this codegolf question 
--it would return 0 in other cases; suppose Axiom ord() return 97..122 for a..z (ascii)
ff(x:String):NNI==
   c:=96;i:=0;k:=1
   repeat
      c:=c+1; i:=i+1           -- c='a'=97 i=1 k=1
      for j in 1..i repeat
               k>#x or ord(x.k)~=c=>return 0
               k:=k+1
      c=122=>break -- c==122 is 'z'
   k=#x+1=>42
   0

Answer 6

Java 8, 103 101 87 bytes

s->{String r="";for(char c=96,i;++c<123;)for(i=96;i++<c;)r+=c;return r.equals(s)?42:0;}

Returns 0 for everything that doesn't match the expected input.

Explanation:

Try it here.

s->{                       // Method with String parameter and integer return-type
  String r="";             //  String starting empty
  for(char c=96,i;++c<123;)//  Loop (1) over the lowercase alphabet:
    for(i=96;i++<c;)       //   Inner loop (2) `c-i` amount of times:
      r+=c;                //    Append that many of the current letter to the String
                           //   End of inner loop (2) (implicit / single-line body)
                           //  End of loop (1) (implicit / single-line body)
  return r.equals(s)?      //  If the input equals the String:
    42                     //   Return 42
   :                       //  Else:
    0;                     //   Return 0
}                          // End of method

Answer 7

JavaScript, 86 Bytes

c="";for(x=0;x<26;)c+=String.fromCharCode(x+97).repeat(++x);alert(prompt("")==c?42:0);

White spaced:

c="";
for(x=0;x<26;)
    c+=String.fromCharCode(x+97).repeat(++x);
alert(prompt("")==c?42:0);

I couldn't indent by 4 spaces for some reason. Not sure if using alert is allowed.

Edit: Fixed indent

Answer 8

Python 3, 58 bytes

lambda s:[42][''.join([i*chr(i+96)for i in range(27)])!=s]

Try it online!

Six years late to the party?

golfed 4 bytes off when I realized I could've used != instead of 1- ==

Answer 9

Jelly, 9 bytes

ØaxJ¤⁼×42

Try it online!

There is already a 13 byte Jelly answer, but the user had their account deleted, and it felt wrong to just edit in this code.

How it works

ØaxJ¤⁼×42 - Main link. Argument: s (string)   e.g. "abc"
Øa  ¤     - Yield the lowercase alphabet           "abc...xyz"   
   J      - Yield range(length)                    [1 2 ... 25 26]
  x       - Repeat (vectorising).                  "abbccc..."
     ⁼    - Equal to the input? Call the A         0
      ×42 - Multiply 42 by A                       0

Answer 10

Pyth - 21 Bytes

V26=Y+Y*@GNhN;IqsYz42  

Explanation:

V26=Y+Y*@GNhN;IqsYz42  z is initialised to input and Y to empty list
V26                    For N from 0 to 25
   =Y                  Set Y to
      Y                Y
     +                 Plus
        @GN            Item N of the alphabet
      *                Times
           hN          N plus one
             ;         End For
              I        If
                sY     Concatenate all elements of Y       
               q       Equals
                  z    z  
                   42  Print 42   

Answer 11

Javascript (ES6) 84 bytes

s=>[...Array(26)].map((_,i)=>String.fromCharCode(97+i).repeat(i+1)).join("")==s?42:0

I don't think an explanation is needed, but here's one anyway:

s=> // input
    [...Array(26)] // preparing alphabet array
    .map((_,i)=>String.fromCharCode(97+i).repeat(i+1)) // using the current index to get the corresponding letter and repeat it as many times as it's 1-index
    .join("")==s?42:0 // Join the array into a string and check if equal to input.

Answer 12

APL NARS 14 chars

{⍵≡⎕a/⍨⍳26:42}

it return 42 for the request string, nothing if something else.

  f←{⍵≡⎕a/⍨⍳26:42}
  w←(⍳26)/⎕a
  f 2
  f w
42
  f 'str'
  

Answer 13

Japt, 13 12 11 bytes

Outputs 42 or false.

;¶CËpEÄé#*

Try it online

Answer 14

AWK, 65 bytes

{for(;i<26;)for(j=++i;j--;)L=L sprintf("%c",i+96);$0=L==$0?42:0}1

Try it online!

Maybe I should develop a golfing version of AWK, but until then, here is my AWK solution :)

Answer 15

K (oK), 14 bytes

Solution:

42*(&!27)~-96+

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Explanation:

Returns 42 if the input matches the "abbccc..." otherwise 0.

42*(&!27)~-96+ / the solution
          -96+ / subtract 96 from the input (vectored)
         ~     / matches?
   (&!27)      / where (&) til (!) 27. Generates 1 2 2 3 3 3 4 4 4 4... sequence
42*            / multiply result (0 false or 1 true) by 42

Answer 16

Python 2, 69 bytes

x=""
for i in range(26):x+=chr(97+i)*(i+1)
if raw_input()==x:print 42

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Answer 17

Julia 0.6, 55 bytes

s->join("$c"^i for (i,c) in enumerate('a':'z'))==s?42:0

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Answer 18

Lua, 80 bytes

c=""for i=1,26 do c=c..string.char(i+96):rep(i)end print(c~=io.read()and""or 42)

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Brief explanation: creates the string and then compares it with the input. Output is an empty string or 42.

Answer 19

Wren, 72 bytes

Generate the range 'a'..'z'. Multiply the string-converted value by the value - 96. Join the list. Check whether the input is equal to this string.

Fn.new{|A|A==(1..26).map{|x|String.fromCodePoint(x+96)*(x)}.join()?42:0}

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Answer 20

Thunno 2, 9 bytes

Ạdż×J=42×

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Explanation

Ạdż×J=42×  # Implicit input
Ạd         # Lowercase alphabet, split into a list of characters
  ż×       # Each multiplied by their 0-based index
    J=     # Equals the input string?
      42×  # Multiply by 42
           # Implicit output