Pandigital Doubling

Question

Inspired by this CMC

Given a positive integer greater than 0, perform the following operation on it:

• If all ten single digits (1234567890) are in the number at least once, output the count and exit the program
• Otherwise, double the number and repeat, incrementing the count.

The count starts at 0 and is the number of times the input was doubled. For example, if the input were 617283945, it would need to be doubled once because 1234567890 has all 10 digits in it.

This is a code-golf so shortest code wins. Input may be taken as a string, if you want.

Test cases

input => output

617283945 => 1
2 => 67
66833 => 44
1234567890 => 0
100 => 51
42 => 55

Answer 1

Python 3, 39 bytes

f=lambda n:len({*str(n)})<10and-~f(n*2)

Try it online!

Outputs False for 0.

Answer 2

05AB1E, 11 10 bytes

-1 byte thanks to scottinet

[D9ÝåË#·]N

Try it online! or as a Test Suite

[          // Start infinity loop
 D         // Duplicate current value (or input)
  9Ý       // Push [0,1,2,3,4,5,6,7,8,9]
    å      // Does each exist in the current value
     Ë#    // Break if all equal (if every digit exists)
       ·   // Else double the current value
        ]N // End loop and print the number of times through the loop

Answer 3

J, 24 23 bytes

(]1&(+$:)2**)10>#@~.@":

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Explanation

(]1&(+$:)2**)10>#@~.@":  Input: integer n
                     ":  Format as string
                  ~.@    Unique
                #@       Length
             10>         Less than 10
           *             Multiply, gives n if previous was true, else 0
         2*              Multiply by 2
 ]                       Get the previous condition
  1&(   )                Execute this if true on 2n, else return 0
      $:                   Recurse
  1  +                     Add 1

Answer 4

Perl 6, 31 28 bytes (27 chars)

-3 bytes thanks to @Joshua

{($_,2×*...*.comb.Set>9)-1}

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Explanation: Still the same construct to recursively generate lists. The first element is the given number ($_), each next element is 2 times the previous (2×* — we use ×, because, although 2 byte character, it's still 1 byte cheaper than 2 * *), and we do this until the end condition of *.comb.unique>9 is satisfied, i. e. when there is more than 9 unique characters in the number. (Technically, we break the string down to a list of characters with .comb, force it to a set with .Set (of course, Sets contain each element only once), and compare with 9, which forces the set into numerical context, which in turn gives its number of elements.)

Finally, we subtract 1 from this list. Again, the list is forced into numerical context, so what we return is 1 less than the length of that list.

Answer 5

JavaScript (ES6) + big.js, 84 74 73 70 bytes

Thanks @ConorO'Brien for saving 10 bytes by suggesting big.js instead of bignumber.js
Thanks to @Rick Hitchcock for -1 byte
Thanks to @Shaggy for -3 bytes

f=n=>[..."4"+2**29].every(d=>RegExp(d).test(c=Big(n)))?0:1+f(c.mul(2))

Takes input as string; supports up to around 2⁶⁹ due to automatic scientific notation conversion occurring beyond that point.

Test Snippet

f=n=>[..."4"+2**29].every(d=>RegExp(d).test(c=Big(n)))?0:1+f(c.mul(2))

;[617283945, 2, 66833, 1234567890, 100, 42].forEach(t=>console.log(`f(${t}) = `+f(t)))

<script src="https://cdn.rawgit.com/MikeMcl/big.js/c6fadd08/big.min.js"></script>

Infinite range, 106 88 87 84 bytes

By using the config option to effectively disable scientific notation when converting numbers to strings, we can have nearly infinite range.

f=n=>[..."4"+2**29].every(d=>RegExp(d).test(c=Big(n)),Big.E_POS=1e9)?0:1+f(c.mul(2))

let num = `${Math.random()*1e6|0}`.repeat(100)
O.innerText=`f(\n${num}\n) = ${f(num)}`

<script src="https://cdn.rawgit.com/MikeMcl/big.js/c6fadd08/big.min.js"></script>
<pre id=O style="width:100%;white-space:normal;overflow-wrap:break-word"></pre>

Answer 6

Jelly, 12, 11 bytes

QLn⁵
ḤÇпL’

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Gotta go fast!

Explanation:

        # Helper link, takes one argument 'z'
Q       # The unique digits of 'z'
 L      # Length
  n     # Does not equal
   ⁵    # 10
        #
        # Main link
  п    # While <condition> is true, run <body> and return all intermediate results
        # Condition:
 Ç      #   The helper link
        # Body:
Ḥ       #   Double the input
        # Now we have a list of all the 'z's that we passed to the helper link
    L   # Return it's length
     ’  # minus one

Answer 7

J, 43 bytes

f=:(,$:@+:@{.)`[@.(9<[:#@~.10&#.inv)
<:@#@f

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Defines an anonymous function. Collects results quite suboptimally. Check out miles's superior answer here!

Answer 8

Haskell, 46 bytes

f n|all(`elem`show n)['0'..'9']=0|1<3=1+f(2*n)

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Answer 9

Clojure, 115 89 82 bytes

-26 bytes by just using a string to represent the list of characters (duh, in retrospect), and changing from using recursion to loop, which allowed me to make a couple of optimizations.

-7 bytes by getting rid of the call to bigint. Apparently we only need to handle input that won't cause an overflow.

#(loop[n % c 0](if(empty?(remove(set(str n))"1234567890"))c(recur(* 2 n)(inc c))))

Pregolfed:

(defn pan [num]
  (loop [n num
         cnt 0]

    ; Remove all the characters from the stringified input
    ;  that are numeric. If the result is an empty list, all
    ;  the numbers were present.
    (if (empty? (remove (set (str n)) "1234567890"))
      cnt
      (recur (* 2 n) (inc cnt)))))

Answer 10

Haskell, 44 bytes

until(\c->all(`elem`show(n*2^c))['0'..'9'])(+1)0

Answer 11

Retina, 85 bytes

^\d*
$&¶$&
D`.(?=.*¶)
\d{10}¶\d+|\d*¶

[5-9]
#$&
T`d`EE
T`_d#`d_`\d#
#
1
}`\d\b
$&@
@

Try it online! Link includes test cases. Slightly optimised for run time. Explanation:

^\d*
$&¶$&

Duplicate the input number.

D`.(?=.*¶)

Deduplicate the digits in the first copy.

\d{10}¶\d+|\d*¶

If 10 digits remain, delete both numbers, otherwise just delete the first copy. Note that deleting both numbers causes the rest of the loop to no-op.

[5-9]
#$&

Place a # before large digits.

T`d`EE

Double each digit.

T`_d#`d_`\d#

Add in the carries.

#
1

Deal with a leading carry.

}`\d\b
$&@

Append an @ and loop until all 10 digits are found.

@

Print the number of @s added.

Answer 12

Java 8, 132 110 87 74 bytes

n->{int c=0;for(;(n+"").chars().distinct().count()!=10;n*=2)c++;return c;}

-57 bytes thanks to @OlivierGrégoire.

Explanation:

Try it here. (Note: test case for 2 is disabled because it should stop at 2⁶⁸, but the size of long is limited to 2⁶³-1.)

n->          // Method with long parameter and integer return-type
  int c=0;   //  Count-integer, starting at 0
  for(;(n+"").chars().distinct().count()!=10;
             //  Loop (1) as long as the unique amount of digits in the number are not 10
    n*=2)    //    After every iteration: multiply the input by 2
   c++;      //   Increase the count by 1
             //  End of loop (1) (implicit / single-line body)
  return c;  //  Return the counter
}            // End of method

---

Old 132 bytes answer using a String input and regex:

n->f(n,0)int f(String n,int c){String t="";for(int i=0;i<10;t+="(?=.*"+i+++")");return n.matches(t+".*")?c:f(new Long(n)*2+"",c+1);}

Try it here. (Note: test case for 2 is disabled because it causes a StackOverflowException due to slightly too much recursion.)

The total regex to check if the String contains all 9 digits becomes ^(?=.*0)(?=.*1)(?=.*2)(?=.*3)(?=.*4)(?=.*5)(?=.*6)(?=.*7)(?=.*8)(?=.*9).*$, which uses a positive look-ahead for the entire String.

Answer 13

APL (Dyalog Unicode), 19 + 2 = 21 bytes

0∘{∧/⎕D∊⍕⍵:⍺⋄⍺+1∇2×⍵}

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This is a dyadic Dfn (direct function), taking 0 as its left argument and the integer as the right. Since the input is supposed to be only the integer, I added 2 bytes for the argument 0∘ to the byte count.

f← is not included in the byte count, since it's not necessary. It just makes it easier to build the test cases.

How it works:

The headers: I removed those from the byte count after some chatting in the APL room, since the function does what it's supposed to do and the results are only incorrect because of the default settings of APL's REPL.

⎕FR←1287 Sets the Float Representation to 128-bit decimal (7 is the code for decimal in APL's REPL). ⎕PP←34 Sets the Print Precision to 34 digits. Both of these are needed, since APL's default representation for big numbers transforms them to scientific notation (e.g. 3.14159265359E15) which messes up the code big time.

0∘{∧/⎕D∊⍕⍵:⍺⋄⍺+1∇2×⍵} ⍝ Dyadic Dfn
0∘                     ⍝ Fixes 0 as the left argument  
          :            ⍝ If
     ⎕D                ⍝ String representation of all digits [0, 9]
       ∊               ⍝ "is in"
        ⍕⍵             ⍝ String representation of the input
   ∧/                  ⍝ AND-reduction. Yields 1 (true) iff all digits are in the right argument.
           ⍺           ⍝ return the left argument
            ⋄          ⍝ Else
                 2×⍵   ⍝ Double the right arg
             ⍺+1       ⍝ increment the left arg
                ∇      ⍝ Recursively call this function with the new arguments.

Answer 14

Husk, 10 bytes

←Vö>9Lud¡D

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Explanation

        ¡D    Repeatedly double the input, collecting results in a list
 V            Return the first index where the following is true
     L          The length of
       d        the digits
      u         with duplicates removed
  ö>9           is greater than 9
←             Decrement (as Husk uses 1-indexing)

Answer 15

Mathematica, 59 48 47 46 38 bytes

-9 bytes thanks to Jenny_mathy.

If[!FreeQ[DigitCount@#,0],#0[2#]+1,0]&

Try it online using Mathics!

Answer 16

PowerShell, 70 69 bytes

for($n=[bigint]$args[0];([char[]]"$n"|group).count-le9;$n*=2){$i++}$i

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(Nearly twice as long as the Python answer :-\ )

Takes input $args[0], casts it as a [bigint], saves it to $n. Enters a for loop. Each iteration we check against whether the $number converted to a string then to a char-array, when Group-Object'd together, has a .count -less than or equal to 9. Meaning, the only way that it equals 10 is if at least one digit of every number 1234567890 is present. If yes, we exit the loop. If not, we $n*=2 and continue. Each iteration inside the loop, we're simply incrementing $i. When we exit the loop, we simply output $i.

Note that for input like 1234567890 where every digit is already accounted for, this will output nothing, which is a falsey value in PowerShell, and equivalent to 0 when cast as an [int]. If that's not OK, we can simply put a + in front of the output $i to explicitly cast it as an integer.

Saved a byte thanks to Roland Heath.

Answer 17

R, 74 bytes

function(x){while(!all(0:9%in%el(strsplit(c(x,""),"")))){F=F+1;x=2*x};F*1}

Try it online! Note that R will give the wrong answer to f(2) due to limitations of how the language stores large integers.

Explanation: For the test of pandigitality, the input is coerced to a character vector by joining with an empty string and then split into individual digits. We then check whether all of 0:9 are present in the resulting vector; if not, we increment the counter, double the input and repeat.

The counter uses F which initialises as FALSE. To make sure it is coerced to numeric, we multiply by one before returning.

Answer 18

Pyth, 11 bytes

f>l{`.<QT9Z

Test suite.

First natural number T where input << T meets the requirement.

Answer 19

Perl 5, 52 + 1 (-p) = 53 bytes

$/=10;for$i(0..9){$/-=/$i/}$_*=2;++$\;$/&&redo}{$\--

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Answer 20

Perl, 43 + 1 bytes

for$x(0..9){$_*=2,++$\,redo LINE if!/$x/}}{

Using the -p flag. This builds on the solution provided by Xcali above.

Answer 21

Swift 4, 111 bytes

func p(_ x:Int,_ c:Int=0)->Int{if !(String(Set(String(x)).sorted())=="0123456789"){return p(x*2,c+1)};return c}

Note: Won't work for x = 2, because of overflow.

Explanation - Input x is first typecasted to string. Then Set() removes the repeating characters. Then it is sorted to match the result. If it doesn't match, x is doubles and counter is incremented.

Answer 22

Japt, 15 bytes

LÆ*2pXÃbì_â Ê¥A

Try it

---

Explanation

Implicit input of integer U.

LÆ    Ã

Create an array of integers from 0 to 99 and pass each through a function where X is the current element.

*2pX

U multiplied by 2 raised to the power of X.

b

Get the index of the first element thay returns true when passed through the following function.

ì_â

Split to an array of digits and remove the duplicates.

Ê¥A

Get the length of the array and check for equality with 10.

---

Alternative, 15 bytes

@*2pX)ìâ sÊ¥A}a

Try it

---

Explanation

Implicit input of integer U.

@            }a

Starting with 0, return the first number that returns true when passed through the following function, with X being the current number.

*2pX)

As above, multiply U by 2 to the power of X.

ìâ

Split to an array of digits, remove duplicates and rejoin to an integer.

sÊ

Convert to a string, get the length and convert back to an integer.

¥A

Check for equality with 10.

Answer 23

Ruby, 46 45 39 38 bytes

def f n;n.digits.uniq[9]?0:1+f(n*2)end

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Updates:

1. -1 by using def f n; instead of def f(n);.
2. -6 by using …[9] instead of ….size==10
3. -1 by removing a semicolon

Answer 24

QBIC, 48 bytes, nc

{q=1[z|q=q*instr(!:$,!a-1$)]~q>0|_Xp\p=p+1┘b=b*2

This should work, in theory. However, in practice this fails because QBasic casts ten-digit numbers (at least needed to get all digits) to scientific notation... I've marked it as non-competing because of that.

Explanation

{             DO ad infinitum
q=1           set q to 1
[z|           FOR a = 1 to 10
q=q*instr     multiply q by the position
(!:$             - in 'b' (read from cmd line at start) cast to string (! ... $)
,!a-1$)          - of the number a-1 [0-9] cast to string
]             NEXT
~q>0          IF any character was not found, instr gave a 0. If q != 0 all digits were present
|_Xp          THEN quit, printing  p (is 0 at start)
\p=p+1        ELSE increase step counter p
┘b=b*2        and double 'b'

Answer 25

GNU dc, 61 bytes

Input is copied from top of stack (which must be otherwise empty); output is pushed to top of stack.

[I~1r:ad0<s]ss[d1+r;a1=p]sp[d2*lfx]sh[0Sadlsxlpx11!=h]dsfxz1-

Explanation

We use the array variable a, storing a 1 in a[d] if digit d is present, otherwise falling back to 0 there. We use the GNU extension ~ to obtain quotient and remainder in a single command.

# populate a[0-9] from the digits
[I~1r:ad0<s]ss

# check pandigit
# return 1 more than lowest unset element of a[]
# start with stack=0
[d1+r;a1=p]sp

# Test for pandigit; double and repeat if needed
[dd+lfx]sh
[0Sadlsxlpx11!=h]dsfx

# We left one value on the stack for each doubling, plus the original
z1-

As a bonus, this will work in arbitrary number bases (not only decimal): simply set the input radix as required (the constant 11 in the definition of f will be read using that number base, so is automatically correct).

Test

for i in 617283945 2 66833 1234567890 100 42
do
    printf '%s => ' $i
    dc -e $i \
       -e '[I~1r:ad0<s]ss[d1+r;a1=p]sp[dd+lfx]sh[0Sadlsxlpx11!=h]dsfxz1-' \
       -e p
done

617283945 => 1
2 => 67
66833 => 44
1234567890 => 0
100 => 51
42 => 55

Answer 26

REXX, 57 bytes

arg n
do b=0 while verify(0123456789,n)>0
  n=n*2
  end
say b

Answer 27

q/kdb+, 33 bytes

Solution:

(#)1_{x*2 1 min!:[10]in 10 vs x}\

Examples:

q)(#)1_{x*2 1 min!:[10]in 10 vs x}\[100]
51
q)(#)1_{x*2 1 min!:[10]in 10 vs x}\[1234567890]
0
q)(#)1_{x*2 1 min!:[10]in 10 vs x}\[42]
55

Explanation:

All the bytes are in the equality, might be able to golf this one down a little further. Utilises q's scan adverb:

count 1_{x*2 1 min til[10] in 10 vs x}\ / ungolfed solution
        {                            }\ / scan over this lambda until it yields same result
                              10 vs x   / convert to base 10
                           in           / left list in right list, returns boolean list
                   til[10]              / range 0..9
               min                      / return the minimum of the list, 0 or 1
           2 1                          / list (2;1) indexed into with 0 or 1
         x*                             / return x multiplied by either 2 or 1
      1_                                / 1 drop, drop one element from front of list
count                                   / count the length of the list

Notes:

If we drop to the k prompt then we can have a 25 byte solution. Converts the number to a list of characters:

q)\
  #1_{x*2 1@&/($!10)in$$x}\[100]
51