Russian Roulette

Question

Write a program which plays Russian Roulette!

If the program is started,

• there should be a 5 in 6 chance of it ending normally after printing "I survived!"
• there should be a 1 in 6 chance of the program crashing. (segmentation fault, etc.)

No input, and no other outputs are allowed.

The randomness must be fair: it must have a uniform probability distribution. This means an uninitialized variable (or a RNG without seed) MOD 6 will not be sufficient.

If the solution works with only one dedicated operating system / platform, you will receive a 6 byte penalty to the score.

_{Shortest code wins, not sooner than 10 days after first valid answer.}

Answer 1

J, 18

'I survived!'[q:?6

Failing with domain error when trying to factorise 0.

Answer 2

PHP 38 bytes

<?~$$s[rand(+$s=sssss,5)]?>I survived!

Placing a + before a non-numeric string will evaluate to 0. Should rand(0,5) return 5, $s[rand(0,5)] will be the empty string (since $s is only five characters long), and subsequently $$s[rand(0,5)] will be an uninitialized variable. Attempting to take the inversion will halt on Unsupported Operand Type. Any other value, 0-4 will return s, and because $s is defined, you will survive.

Note: as of php version 4.2.0, the random number generator is seeded automatically.

Answer 3

vba, 27

?1/int(6*rnd),"I Survived!"

used in immediate window.
On failure, an error window stating:

appears

Answer 4

Befunge - 48 chars

 v >91+"!devi"v
/?>?<v"I surv"<
 / / :
   :,_@#

Befunge's only randomness is the ? operator, which sends you heading in one of four posible directions (1/4 chance). By blocking one or two directions, you have 1/3 or 1/2 chance, and by combining these, you get 1/6 chance to get out of the program "alive".

The program crashes by doing a divive-by-zero. I guess it's implementation-specific what will happen (on Wikipedia it says the program should ask for the desired answer), but befungee.py sort of crashes, or exits angrily:

$ for i in {1..6} ; do ./befungee.py roulette.befunge ; done
Error (1,2): integer division or modulo by zero
Error (3,2): integer division or modulo by zero
Error (1,2): integer division or modulo by zero
I survived!
Error (0,1): integer division or modulo by zero
I survived!

Answer 5

Ruby, 24-28

p rand(6)<5?"I survived!":1/0

Approx each 6 time, there is a ZeroDivisionError

There is even a shorter version with 24 characters (Thanks to ugoren and histocrat):

6/rand(6);p"I survived!"

If you don't accept the " in the output, then I need 3 more characters. The first option (puts) adds a newline, the second ($><<) makes no newline:

6/rand(6);puts"I survived!"
6/rand(6);$><<"I survived!"

There is a question about random number in ruby at SO. The seed with srand is automatically called with the seed being from the current time if it wasn't already called. (see Julians comment)

---

Primo had the idea for an extra bonus to those solutions which don't rely on division by zero.

My first solution can be shortened (28 characters) with a undefined local variable or method ``a' for main:Object (NameError)

p rand(6)<5?"I survived!":a

Answer 6

Dyalog APL - 25 22 21 20 Charachters

'I Survived!'⊣1÷6⊤?6

Prints DOMAIN ERROR as the error, due to division by zero.

Shortest non-division by zero solution I could come up with is 23 characters.

('I Survived!'1)[~6⍷?6]

It throws an INDEX ERROR

Try it here

APL Font here

Answer 7

Python, 96

from ctypes import*
from random import*
randrange(5)or pointer(c_int())[9**9]
print'I survived!'

If randrange(5) returns 0, then python will crash due to a segmentation fault.

Answer 8

R 30

"I survived!"[6*runif(1)<5||Z]

One time out of six, it will throw an error: Error: object 'Z' not found

Answer 9

GolfScript, 21 chars

,6rand/;'I survived!'

Like most of the answers, this one has a one in six chance of crashing with a ZeroDivisionError. The shortest solution I could manage without using division by zero is 23 chars:

5,6rand=+;'I survived!'

which has a 1/6 chance of crashing with undefined method `+' for nil:NilClass (NoMethodError).

(Ps. While developing this, I found what might be a bug in the GolfScript interpreter: code like 0,1> appears to leave a nil value on the stack, which will later crash the program if you try to do anything with that value except pop it off and throw it away with ;. Unfortunately, the fact that I do need to use the value somehow to trigger a crash means that even exploiting this bug didn't help me get below 23 chars.)

Answer 10

Python, 70 characters

With inspiration from grc's answer.

from random import*
if randrange(5)<1:exec'()'*9**5
print'I survived!'

randrange(5) returns a value between 0 and 5.
If it returns a 0, Python crashes while attempting to exec(ute) a string of code that contains 9^5 sets of parentheses.

Answer 11

Javascript, 42

(Math.random()*6|0)?alert('i survived!'):b

The bitwise or floors the result of the multiplication thus a value between 0 and 5 results. 0 gets implictly casted to false, so in 5 of 6 cases the alert appears in the 6th case a certain b is referenced, crashing the process.

Answer 12

Using the usual divide by zero method:

Perl 5.8 Version

1/(int rand 6)&&print "I survived!"

Perl 5.10 Version

1/(int rand 6)&&say "I survived!"

On failure, these will display:

Illegal division by zero at -e line 1.

Using the bless function which is used for creating objects in perl.

Perl 5.8 Version

print (int rand 6?"I survived!":bless me);

Perl 5.10 Version

say (int rand 6?"I survived!":bless me);

On failure, these will display:

Can't bless non-reference value at -e line 1.

Answer 13

R, 50 44 42 36

ifelse(!is.na(sample(c(NA,1:5),1)),'I Survived!',)

ifelse(floor(runif(1,0,5))>0,'I Survived!',)

ifelse(floor(runif(1,0,5)),'I Survived!',)

ifelse(sample(0:5,1),'I Survived!',)

Death Err Message:

Error in ifelse(!is.na(1/sample(c(NA, 1:5), 1)), "I Survived!", ) : argument "no" is missing, with no default

Answer 14

Emacs-Lisp, 42 characters

(if (= (random 6) 5) 
    z (message "I survived!")
    )

Answer 15

Javascript, 40 chars

In Javascript the divide-by-zero trick doesn't even work: it just returns Infinity. Therefore, referencing a non-existing variable:

alert(6*Math.random()|0?"I survived!":f)

Not so short, though fun :)

Answer 16

PHP - 30 bytes

<?rand(0,5)?:~[]?>I survived!

Requires PHP 5.4+ for the short array syntax, invalid operator idea shamelessly stolen from @primo.

As stated, rand() is automatically seeded on first use.

Answer 17

Befunge, 38

v>25*"!devivrus I",,,,,,,,,,,@
?^
v
?^
<1

Pretty straight-forward. Crashing is done by pushing 1s onto the stack until it overflows. I made a few attempts at cutting out those 11 commas and replacing them with some more efficient loop to print everything, but couldn't get it under 11 characters.

Note that counting characters in Befunge is a little tricky... For instance there's only one character on the third line, but I'm counting an extra one there since execution could travel through that location.

Answer 18

C, 67 65 62 chars

rand()%8 doesn't lose fairness. Division crashes for t=0, gives true for 1 and 2 (retry), gives false for 3..7 (survived).
EDIT: The previous version used a temporary variable, which ended up completely unneeded. 2/(rand()%8) implements both needed conditions.

main(){
        for(srand(time(0));2/(rand()%8););
        puts("I survived!");
}

Answer 19

CMD Shell (Win XP or later), 40 +6

I'm only doing this one because DOS is not something that should even be thought of for code golf, and the whitespace is important

set/a1/(%RANDOM% %% 6)&&echo I Survived!

On failure, it will print

Divide by zero error.

Answer 20

Java, 149

public class R{public static void main(String[]s){int[]a={1,1,1,1,1};System.out.println(a[new java.util.Random().nextInt(7)]>0?"I survived!":"");}}

Fails with an "Array out of bounds" error. Managed to shave a few characters by using anonymous Random object (no imports).

Answer 21

Groovy, 39

1/new Random().next(6);print"I survived!"

Picks a random number between 0 and 5 inclusive. If 0, throws a divide by zero exception.

Answer 22

T-SQL 56 44 40 + 6

 if 1/cast(ceiling(rand()*6)-1as int)<2print'I Survived!'

Credit Sean Cheshire for calling out cast as unnecessary

 if 1/ceiling(rand()*6-1)<2print'I Survived!'

Credit personal message from Sean Cheshire for suggestion to change ceiling to floor.

 if 1/floor(rand()*6)<1print'I Survived!'

Death Err Msg: Msg 8134, Level 16, State 1, Line 3 Divide by zero error encountered.

Answer 23

Python (56), Haskell (77)

This crashes with an IndexError when the generated number is 1:

from random import*
print['I survived!'][1/randint(1,7)]

The Haskell solution has the same idea:

import System.Random
main=putStrLn.(["I survived!"]!!).div 1=<<randomRIO(1,6)

Answer 24

Python, 59 55 53, 65 59 56

import os
1/(ord(os.urandom(1))%6)
print"I survived!"

ZeroDivisionError when ord(os.urandom(1))%6 evaluates to 0

import os
print(["I survived!"]*5)[ord(os.urandom(1))%6]

IndexError when ord(os.urandom(1))%6 evaluates to 5

Answer 25

VBA - 39/46

I don't love Sean Cheshire's numeric output (though still a good answer, it technically fails the No input, and no other outputs are allowed. from the spec...), plus he uses /0, so here are my alternatives:

?Mid("I Survived!",IIf(Int(6*Rnd),1,0))

This resolves to a Run-time error '5': Invalid procedure when trying to reach character 0 (VBA is 1-based indexing).

n="I Survived!":If Int(6*Rnd) Then ?n Else ?-n

This resolves to a Run-time error '13': Type mismatch when applying a negative switch to a string.