Two Makes All The Difference - Cops

Question

NOTICE - This challenge is now closed. Any new answers will be ignored and the accepted answer will not change

Challenge

Write a valid program which, when just two characters in the program are changed, removed or added, completely changes the output.

The changed output must have a Levenshtein Distance of 15 or more from your original output.

The output must be non empty and finite. Your program therefore must terminate within 1 minute.

Your output must be deterministic, outputting the same thing each time you run the program. It also must not be platform dependent.

Any hash functions are disallowed, as are built in PRNGs. Similarly, seeding an RNG is not allowed.

After a period of three days, an uncracked submission will become safe. In order to claim this safety, you should edit your answer to show the correct answer. (Clarification: Until you reveal the answer, you are not safe and can still be cracked.)

Formatting

Your answer should be in the following format:

# <Language name>, <Program length>

## Code

<code goes here>

## Original Output

<output goes here>

## Changed output

<changed output goes here>

Robbers

The robbers' challenge is to find out which two characters you have changed. If a robber has cracked your solution, they will leave a comment on your answer.

You can find the robbers' thread here.

Winning

The person with the shortest uncracked solution wins.

Leaderboard

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script><script>site = 'meta.codegolf';postID = 5686;isAnswer = false;QUESTION_ID = 54464;var safe_list=[];var uncracked_list=[];var n=0;var bycreation=function(x,y){return (x[0][0]<y[0][0])-(x[0][0]>y[0][0]);};var bylength=function(x,y){return (x[0][1]>y[0][1])-(x[0][1]<y[0][1]);};function u(l,o){ jQuery(l[1]).empty(); l[0].sort(o); for(var i=0;i<l[0].length;i++) l[0][i][1].appendTo(l[1]); if(l[0].length==0) jQuery('<tr><td colspan="3" class="message">none yet.</td></tr>').appendTo(l[1]);}function g(p) { jQuery.getJSON('//api.stackexchange.com/2.2/questions/' + QUESTION_ID + '/answers?page=' + p + '&pagesize=100&order=desc&sort=creation&site=codegolf&filter=!.Fjs-H6J36w0DtV5A_ZMzR7bRqt1e', function(s) { s.items.map(function(a) { var he = jQuery('<div/>').html(a.body).children().first(); he.find('strike').text(''); var h = he.text(); if (!/cracked/i.test(h) && (typeof a.comments == 'undefined' || a.comments.filter(function(b) { var c = jQuery('<div/>').html(b.body); return /^cracked/i.test(c.text()) || c.find('a').filter(function() { return /cracked/i.test(jQuery(this).text()) }).length > 0 }).length == 0)) { var m = /^\s*((?:[^,;(\s]|\s+[^-,;(\s])+)\s*(?:[,;(]|\s-).*?([0-9]+)/.exec(h); var e = [[n++, m ? parseInt(m[2]) : null], jQuery('<tr/>').append( jQuery('<td/>').append( jQuery('<a/>').text(m ? m[1] : h).attr('href', a.link)), jQuery('<td class="score"/>').text(m ? m[2] : '?'), jQuery('<td/>').append( jQuery('<a/>').text(a.owner.display_name).attr('href', a.owner.link)) )]; if(/safe/i.test(h)) safe_list.push(e); else uncracked_list.push(e); } }); if (s.length == 100) g(p + 1); else { var s=[[uncracked_list, '#uncracked'], [safe_list, '#safe']]; for(var p=0;p<2;p++) u(s[p],bylength); jQuery('#uncracked_by_length').bind('click',function(){u(s[0],bylength);return false}); jQuery('#uncracked_by_creation').bind('click',function(){u(s[0],bycreation);return false}); } });}g(1);</script><link rel="stylesheet" type="text/css" href="//cdn.sstatic.net/codegolf/all.css?v=83c949450c8b"><style>table th,table td { padding: 5px;}th { text-align: left;}.score { text-align: right;}table a { display: block;}.main { float: left; margin-right: 30px;}.main h3,.main div { margin: 5px;}.message { font-style: italic;}</style><div class="main"><h3>Uncracked submissions</h3><table> <tr> <th>Language</th> <th class="score">Length</th> <th>User</th> </tr> <tbody id="uncracked"></tbody></table><div>Sort by: <a href="#" id="uncracked_by_length">length</a> <a href="#" id="uncracked_by_creation">creation</a></div></div><div class="main"><h3>Safe submissions</h3><table> <tr> <th>Language</th> <th class="score">Length</th> <th>User</th> </tr> <tbody id="safe"></tbody></table></div>

Answer 1

Cracked

VBA, 72 bytes

Sub q()
Dim a(2) As Double
a(0)=-5
a(1)=10
msgbox IRR(a,0.253)
End Sub

Original Output

 0.999999999999136

Adjusted Output

1.82842712474619

Need to see some more VBA representation round here.=) Runs in Excel 2007+

Answer 2

Cracked

bc, 22 bytes

4518574615489737231532

Current output

4518574615489737231532

Desired output

195543687803724

Answer 3

Cracked by Luis Mendo

MATLAB, 62 bytes

Code

mistake=-1;tragic=rosser;a=hilb(8)*42;
a(:,:)+tragic(8)/mistake

Original Output

   13.0000   -8.0000  -15.0000  -18.5000  -20.6000  -22.0000  -23.0000  -23.7500
   -8.0000  -15.0000  -18.5000  -20.6000  -22.0000  -23.0000  -23.7500  -24.3333
  -15.0000  -18.5000  -20.6000  -22.0000  -23.0000  -23.7500  -24.3333  -24.8000
  -18.5000  -20.6000  -22.0000  -23.0000  -23.7500  -24.3333  -24.8000  -25.1818
  -20.6000  -22.0000  -23.0000  -23.7500  -24.3333  -24.8000  -25.1818  -25.5000
  -22.0000  -23.0000  -23.7500  -24.3333  -24.8000  -25.1818  -25.5000  -25.7692
  -23.0000  -23.7500  -24.3333  -24.8000  -25.1818  -25.5000  -25.7692  -26.0000
  -23.7500  -24.3333  -24.8000  -25.1818  -25.5000  -25.7692  -26.0000  -26.2000

Changed Output

  -22.0000   19.0000   11.0000  -50.5000  -51.6000    1.0000   -1.0000  -51.7500
   12.0000  -41.0000  -43.5000   -3.6000   -6.0000  -45.0000  -44.7500  -11.3333
   -3.0000  -36.5000  -37.6000  -13.0000  -15.0000  -37.7500  -37.3333  -19.8000
  -29.5000  -17.6000  -20.0000  -31.0000  -30.7500  -25.3333  -26.8000  -29.1818
  -23.6000  -27.0000  -29.0000  -23.7500  -23.3333  -33.8000  -35.1818  -21.5000
  -34.0000  -17.0000  -16.7500  -39.3333  -40.8000  -15.1818  -14.5000  -44.7692
  -43.0000   -9.7500   -9.3333  -47.8000  -49.1818   -7.5000   -6.7692  -53.0000
   -2.7500  -53.3333  -54.8000   -1.1818   -0.5000  -58.7692  -60.0000    1.8000

Answer 4

Cracked by Luiz Mendo

MATLAB, 40 bytes

Code

format long
arg = [.1 .2 .3];
sin(arg'*exp(9))

Original Output

  -0.220680258232564
  -0.430479305680324
  -0.619052457794081

Changed Output

  -0.803636351328917
  -0.721159584869623
  -0.148487879352133

Hint: there's another solution to this question

Answer 5

Cracked

Javascript, 53 bytes

Code

a=(((b=(a=1)+a)+a)-b-a)*(a=[b])['length'];
alert(a);

Original Output

0

Changed output

5.551115123125783e-18

Tested under: Firefox, Chrome, IE

Answer 6

Cracked

Lua, 55 bytes

Now with less skimpy underwear! This code might look like my last code that was sadly cracked, but I can assure the solution is completely different

G={load="lfkjgGsHjkU83fy6dtrg"}
print(tostring(G.load))

Current output:

lfkjgGsHjkU83fy6dtrg

The correct output on 64 bit machines:

26

And on 32 bit machines:

18

Answer 7

Cracked.

Stuck, 21 Bytes

I'll start with an easy one, since nobody has seen this before and there's no documents.. Anyways, Stuck is a stack-based language, very similar in usage to CJam. All you need to know is:

NR -> creates a range [1,N] on the stack. 
[N]z -> zips together the top 2 lists, unless an optional N is specified, then the top N lists.
] -> Flattens the top list by one "dimension".

For the record, while I have made commits since this challenge happened, all of this functionality has been present long before.

Code:

1R2R3R4R5R6R7R8R9R9z]

Original Output:

(1, 1, 1, 1, 1, 1, 1, 1, 1)

Changed Output:

(1, 1, 1, 1, 1, 1, 1, 1)(2, 2, 2, 2, 2, 2, 2, 2)(3, 3, 3, 3, 3, 3, 3, 3)

Answer 8

Cracked

Ruby, 24

Code

p _=?9;p$.+=1until 9#$./

Original Output

"9"

Changed output

"9"
1
2
3
4
5
6
7
8
9

Answer 9

Befunge 98, 30 Bytes(Safe)

Code

153+:*,+:f`#v_
+ ':_;#:-1;#@;,

Original output:

@@@@@@@@@@@@@@@@

Changed output:

@~}|{zyxwvutsrqponmlkjihgfedcba`_^]\[ZYXWVUTSRQPONMLKJIHGFEDCBA@?>=<;:9876543210/.-,+*)('&%$#"!

Solution

g53+:*,+:f`#v_
+ ':_;#:-1;#<@;,

Answer 10

PowerShell v3, 384 (SAFE)

(My second post ever on PPCG, please be gentle. :) I think I'm going to like this community!)

Code:

$s="a*h*t*s*m*i*d*o*n*l*k*e*y*u*g*r*w*LOOD> AIG BAE>!+<R S!>>+<GH MHN JFKL> LOOD AIG BAE>?<+"
$cur="";$l="";[char]$n="A";$st=@{}
foreach($c in [char[]]$s){switch -regex($c){
"[\*\>]" {$st[$n]=$cur.TrimStart(" ");$n=[char]([int]$n-1);if($c-eq">"){$l+=$cur};$cur=""}
"\+" {$l=$cur;$cur=""}
"\<" {$l+$cur;$l="";$cur=""}
default {if($st.Contains($c)){$cur+=$st[$c]}else{$cur+=$c}}}}

Original output:

eggs and ham!
eggs and ham!
do you like eggs and ham?

Modified output:

!

GH MHN JFKL LOOD aIG BaEt

(to be clear, that's a blank line in the middle of the modified output)

Mini-hint:

h/t to Adam Barr for the inspiration

Edit - Safe - Below is corrected code, and below that is explanation

$s = "a*h*t*s*m*i*d*o*n*l*k*e*y*u*g*r*w*LOOD> AIG BAE>!+<R S!>>+<GH MHN JFKL> LOOD AIG BAE>?<+" # The string we're cycling through
$cur = "" # What word(s) we've currently built
$l = "" # The current line we've finished building
[char]$n = "A" # Cast as a character instead of a string, this is the index of our temporary store
$st = @{} # Our temporary store - the first time through, this will populate out with the first part of the string $s
foreach ($c in [char[]]$s) { # Loop through the string $s as an array, one $c character at a time
    switch -regex ($c) {
        "[\*\>]" {
            $st[$n] = $cur.TrimStart(" ") # Ensures that we're not adding a space, and adds what we've currently built into the store
            $n = [char]([int]$n + 1)    #ONE OF THE CHANGES - Changed the +1 to -1, which causes the indexing of the store to be off
            if ($c -eq ">") { $l += $cur } # If our current character is a >, add that to the line as it's finished
            $cur = "" # Reset what we're building
        }
        "\+" {
            $l += $cur #ONE OF THE CHANGES - Changed the += to =, which causes the line to not get printed
            $cur = "" # Reset what we're building
        }
        "\<" {
            $l + $cur # Add on our current word to the line and print it out
            $l = "" # Reset our line
            $cur = "" # Reset what we're building
        }
        default {
            if ($st.Contains($c)) {
                $cur += $st[$c] # If our store contains the character, add what's in the store's index at $c to our current word
            } else {
                $cur += $c # Else, just add the character to our current word
            }
        }
    }
}

Explanation

The best way to explain this is that we're using the string at the start as a sort of cypher. The first half of the string, demarcated by asterisks, is our cypher results. The rest of the string is the output, encoded based off of the "integer" value of the letter (from an alphabetical perspective, not an ASCII perspective). For example, the LOOD> takes the 12th character (an e), the 15th character (a g) twice, and then the 4th character (a s), which forms the word eggs, then the > case, which trims off what we're building so that our words don't run together.

The script cycles through the string character by character, building the cypher store at first (because of all the asterisks, the first 34 times through the switch causes either the first case or the default case to be called), while the rest of the times through cause either an index lookup (because we've already added that letter) or text manipulation (e.g., the second change which just re-sets a variable rather than print it out).

Please let me know if you have further questions!

Answer 11

Fantom, 30 (safe)

Code

[7115432d/9,219.or(64),37][0]

Original Output

790603.5555555556

Changed output

55

Solution

"7115432d/9,219.or(64),37"[0]

By changing the array to a string literal, the index call actually gets the first character of the string. Characters in fantom are actually just ints, so the value of '7' is 55.

Answer 12

Malbolge, 411 bytes

Code

bCBA@?>=<;:9876543210/.-,+*)('&%$#"!~}|{zyxwvutsrqponmlkjihgfedcba`_^]\[ZYXWVUTSRQPONMLKJIHGFEDCBA@?>=<;:9y76543210/(L,l$H('&%$#"!~}v{zyxwvutm3qponmlkjihgfedcba`_^]?zZYXWVOTSRQPONMFjJIHGFEDC<`@?!=<;4X87w/S3s10/.-,+*)('&%$#"!~}|{zyxq7Xtmrk1onPlkdihg`&dcbD`_^]\[ZYXQutTSRQPONMLKJCgGFEDCBA@?>=<;:z81Uv43210/.'Kl*#G'&f|{A!~}|{zs9qvo5mrqponmle+*hgfe^c\"`_^]\[ZYXWV8Nr5QPONGkKJ,HGFEDCBA@?>=<;:3W76/432+O/o-,+*)('&%|B/

Original output

Two Makes All The Difference

Modified output

Two 

(note the trailing space)

Solution

bCBA@?>=<;:9876543210/.-,+*)('&%$#"!~}|{zyxwvutsrqponmlkjihgfedcba`_^]\[ZYXWVUTSRQPONMLKJIHGFEDCBA@?>=<;:9y76543210/(L,l$H('&%$#"!~}v{zyxwvutm3qponmlkjihgfedcba`_^]?zZYXWcOTSRQPONMFjJIHGFEDC<`@?!=<;4X87w/S3s10/.-,+*)('&%$#"!~}|{zyxq7Xtmrk1onPlkdihg`&dcbD`_^]\[ZYXQutTSRQPONMLKJCgGFEDCBA@?>=<;:z81Uv43210/.'Kl*#G'&f|{A!~}|{zs9qvo5mrqponmle+*hgfe^c\"`_^]\[ZYXWV8sr5QPONGkKJ,HGFEDCBA@?>=<;:3W76/432+O/o-,+*)('&%|B/

Answer 13

Perl, 49 byes (safe)

Code

$_=cos 99;printf"%.16f",0x7275*sin $_/s/[3-8]/04/

Original Output

145.9795577401910975

Changed Output

23.3077670014990304

---

Clue

I tried to do this before but there was another unintended (easier) solution. The robber to my previous challenge may help you solve this one. Try to solve it with three modifications and you'll be half way to the two modification answer.

Solution

$_=cos 99;printf"%.16f",07275*sin $_/y/[3-8]/04/

1. Remove the x to turn hexadecimal 0x7275 (decimal 29301) into octal 07275 (decimal 3773)

2. Change the s/// (replacement) to y/// (transliteration) so that instead of the first digit from 3-8 becoming the string 04, all digits in that range become 4. Additionally, both return the number of changes; the s/// version only makes one change while y/// makes all 8 changes (the way s///g would). If you could change a third character, you could do s/[3-8]/4/g and have the same result as my y/[3-8]/04/. (This was exploited to solve my previous attempt.)

Example of s/// vs y///:

$_="s: 1234567890, ";s/[3-8]/04/;print; $_="y: 1234567890";y/[3-8]/04/;print

s: 12044567890, y: 1244444490

So therefore we're multiplying by a changed number and the function at the end alters the default variable differently and divides by a different number.

Answer 14

Cracked

C++ 91 Bytes

#include <iostream>
int main()
{
    //can you figure it out?
    std::cout << "I like cake and";
}

Output:

I like cake and

Changed output

Answer 15

Cracked

PHP 5.4, 92 bytes

<?php
define('E','!');

$x = 4;
$t = " Hello World";
$t .= E;
$t .= E;
$t .= E;

print($t);

Output:

 Hello World!!!

Changed Output:

 Hello World! Hello World! Hello World! Hello World!

(Note: both outputs include a leading space)

Answer 16

Cracked

Lua, 54 Bytes

G={string="gs_hSDrGSFG5;U*ts"}
print(tostring(G.string))

Current output:

gs_hSDrGSFG5;U*ts

Desired output:

23

Note: I'm not exactly sure why, but if you are using an online compiler (specifically repl.it) the correct output will be 15.

Answer 17

Cracked

PHP, 21 bytes

Code

print_r(range(i,09));

Original Output

Array ( [0] => 0 )

Changed output

Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5 [5] => 6 [6] => 7 )

Answer 18

Fantom, 34

Code

[7115432d/9,219.or(64),37,5555][0]

Original Output

790603.5555555556

Changed output

55

Ok, hopefully this one is a little more competitive than my previous attempt. Levenshtein Distance of 15. Run it in fansh.

Better Code

@isaacg found an easy solution I hadn't even seen. This code removes that solution while keeping the original one I intended, if anyone still wants the challenge.

[7115432d/9,219.or(64),37,55.0f][0]

Answer 19

Cracked

Matlab/Octave, 10 bytes

this should be a fairly easy one.

I only tried it with Octave online, but it should run fine in matlab.

Code:

e^(i*pi)+1

Output

0.0000e+00 + 1.2246e-16i

Changed Output

1.9336e+04

Answer 20

Cracked

Javascript, 169 bytes

Code

a=1,b=a*2,c=a+b,d=[a+b];while(c>b)c-=a;for(i=1;i<=c;i++)d.push(i);i=''+c*d['length']*d['length'];alert(Math[String.fromCharCode(i.charCodeAt(0) * i.charCodeAt(1) / 32)])

Original Output

undefined

Changed output

2.718281828459045

Answer 21

Cracked

Python 2, 57 bytes

Code

i=long;j=map;print reduce(i.__mul__,j(i,j(ord,`i`)))/1234

Original Output

3164217824783520557889

Changed output

9072146982802639849575831250318562874251

Answer 22

Cracked

Python 2, 41 bytes

Code

print sum((ord(i)<<0x156 for i in `sum`))

Original Output

19718712710133388269747721838124583424582966957653854505259504044885223633870136963133245450763229047291904

Changed output

20

Answer 23

Cracked

MATLAB / Octave, 33 bytes

Code

eig(cov(reshape(sin(1:60),5,[])))

Original Output

ans =

   -0.0000
   -0.0000
   -0.0000
   -0.0000
   -0.0000
   -0.0000
    0.0000
    0.0000
    0.0000
    0.0000
    2.4410
    4.5766

Changed Output

ans =

    0.0064
    0.0000
    0.0000
   -0.0000
   -0.0000
    0.0000

Answer 24

Cracked

MATLAB / OCTAVE, 28 bytes

Code:

f=@(x)x^.7;g=@(x)7/f(x);g(7)

Original output:

ans =

    1.7928

Changed output

ans =

  -0.3011 - 0.4144i

Answer 25

Cracked

Clojure, 35 Bytes

Code

(printf "%d\n" 2155263413256326162)

Original Output

2155263413256326162
nil

Changed output

3681347803529195
nil

Answer 26

Cracked

GolfScript, 4 bytes

9,!9

Original output

09

(trailing linefeed)

Modified output

0123456789012345678

(no trailing linefeeed)

---

If you test your code in Web GolfScript, you have to look at the source code of the output, since the (lack of a) trailing linefeed will be undetectable in the rendered page. For the correct solution, there should be no linefeed between 0123456789012345678 and </textarea>.

It might be easier to use the Ruby interpreter for this one.

Answer 27

Cracked

CSS, 53

Code

body:after{counter-reset:a 512;content:counter(a)"₽"}

Original Output

512₽

Changed output

0%

Snippet

body:after{counter-reset:a 512;content:counter(a)"₽"}

Answer 28

Mathematica, 35 bytes (safe)

Code

z=Zeta[4/3,1/2];N[Min[z,Sec[z]],20]

Original Output

1.4508303658284314991

Changed output

-0.72451364607415832407

Edit: Note that the original code will sort-of work on Wolfram Alpha, but the modified code does not.

Changed Code

z=Zeta[4/3,1/2];N[Sin[z,Set[z]],20]

Set[z] evaluates to Sequence[] so Sin[z,Set[z]] = Sin[z]. Moreover, Mathematica evaluates function arguments serially and in order, so Set[z] is evaluated after the value of z is already used.

Answer 29

Cracked

APL, 5 characters

3⍟877

Current output

6.1682424839682115

Modified output

0.20016493054644696

An edit distance of 16.

Answer 30

Python 2/3, 70 bytes (safe)

Code

x=932436
for i in range(99**4):x=(1103515245*x+12345)%2**31
print(x*x)

Original Output

211455574532454121

Changed output

1039038861760158249

Solution

x=9372436
for i in range(59**4):x=(1103515245*x+12345)%2**31
print(x*x)

The solution initializes x to 9372436 instead of 932436, and does range(59**4) instead of range(99**4). As an aside, the solution runs in about 1/10th of the time.

I probably could have made it shorter without making it too much easier, or at all easier.