Missing numbers in arithmetic sum

Question

Challenge

Giving a valid arithmetic sum with some missing numbers, output the full expression.

Example:

    1#3                 123
+   45#     =>     +    456
--------            --------
    579                 579

Input

• Expression format can be an array ["1#3", "45#", "579"], a string "1#3+45#=579", or 3 inputs f("1#3","45#","579")

Output

• Same as input
• You don't need to output the result

Notes

• The missing numbers are going to be represented using # or any other constant non-numeric character you want
• Assume result wont have a missing number
• Assume Input/Output consist in 2 terms and a final result
• Assume both term > 0 and result >= 2
• There might be multiple solutions. You can output anyone as long as the sum result match

Test Cases with possibly outputs (pretty format)

    #79                     879
+   44#         =>      +   444
--------                --------
    1323                   1323

    5#5                     555
+   3#3         =>      +   343
--------                --------
    898                     898

      #                       1
+     #         =>      +     1
--------                --------
      2                       2

    ###                     998
+   ###         =>      +     1     PD: there are a lot of possible outputs for this one
--------                --------
    999                     999


    123                     123
+     #         =>      +     1
--------                --------
    124                     124


      9                       9
+    #6         =>      +    46
--------                --------
     55                      55


    #123651                     1123651
+      #98#         =>      +      7981
------------                -----------
    1131632                     1131632

---

Standard code-golf rules apply

Answer 1

Brachylog, 22 16 bytes

{Ṣ∧Ị∋|}ᵐ²ịᵐ.k+~t

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-6 bytes thanks to @Fatelize

Explanation

{Ṣ∧Ị∋|}ᵐ²ịᵐ.k+~t
{     }ᵐ²                   #   for each letter in each string
 Ṣ∧Ị∋                       #       if " " return a digit; else input
     |                      #
         ịᵐ                 #   cast each string to number
            k+              #   the sum of all but the last one
              ~t            #       is equal to the last one
           .                #   output that list

Answer 2

JavaScript (ES6), 74 57 bytes

Takes input as (a)(b)(result), where a and b are strings with . for unknown digits and result is an integer. Returns an array of 2 integers.

a=>b=>F=(c,n)=>`${r=[c,n]}`.match(`^`+[a,b])?r:F(c-1,-~n)

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Commented

a => b =>                // a, b = term patterns (e.g. a = ".79", b = "44.")
  F = (c,                // c = expected result (e.g. 1323)
          n) =>          // n = guessed value of b, initially undefined
    `${r = [c, n]}`      // we coerce r = [c, n] to a string (e.g. "879,444")
                         // if n is still undefined, this gives just c followed by a comma
    .match(`^` + [a, b]) // we coerce [a, b] to a string, prefixed with "^" (e.g. "^.79,44.")
    ?                    // this is implicitly turned into a regular expression; if matching:
      r                  //   return r
    :                    // else:
      F(c - 1, -~n)      //   decrement c, increment n and do a recursive call

Answer 3

Matlab, 143 134 132 119 115 bytes

function[m]=f(x,y,r),p=@(v)str2num(strrep(v,'#',char(randi([48,57]))));m=[1,1];while sum(m)-r,m=[p(x),p(y)];end;end

-4 bytes thanks to @Luismendo

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---

Pretty big and pretty stupid. It simply replaces all # with random digits until it finds the correct ones.

Answer 4

R, 67 51 bytes

Rock simple and scales horribly, just grep all the sum combinations. Use "." for unknown digits. It won't find the same answer as test case number 4, but it will give a possible answer, which follows the letter of the rules as given.

-16 bytes by grepping after forming the output and replacing paste with the ? operator.

function(x,y,z,`?`=paste)grep(x?y,1:z?z:1-1,v=T)[1]

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Answer 5

Charcoal, 32 bytes

Ｆ²⊞υ0Ｗ⁻ζΣＩυ≔Ｅ⟦θη⟧⭆κ⎇⁼μ#‽χμυ←Ｅυ⮌ι

Try it online! Link is to verbose version of code. Explanation:

Ｆ²⊞υ0

Push two string 0s to the predefined empty list u to get the while loop going.

Ｗ⁻ζΣＩυ

Repeat while the sum of casting the values in u to integer is not equal to the desired result.

≔Ｅ⟦θη⟧

Create an array of the two inputs and map over it.

⭆κ⎇⁼μ#‽χμυ

Replace each # with a random digit and assign the result back to u.

←Ｅυ⮌ι

Print the result right justified. (Left justified would be just υ for a 4-byte saving.)

Answer 6

Jelly, 20 bytes

ØDṛċ¡V€)ŒpḌð€ŒpS⁼¥ƇḢ

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Answer 7

05AB1E (legacy), 23 20 bytes

[²³«εð9ÝΩ:}²gôJDO¹Q#

-3 bytes thanks to @Emigna.

Unknown digits are spaces ( ). Input order should be: expected result; longest string; shortest string.

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Explanation:

[                 # Start an infinite loop
 ²³«              #  Take the second and third inputs, and merge them together
               #   i.e. " 79" and " 4 " → " 79 4 "
    ε     }    #  Map each character to:
     ð   :     #   Replace a space with:
      9ÝΩ      #   A random digit in the range [0,9]
               #    i.e. " 79 4 " → ['3','7','9','2','4','3']
               #    i.e. " 79 4 " → ['5','7','9','7','4','4']
²g             #  Get the length of the second input
               #   i.e. " 79" → 3
  ô            #  And split it into two numbers again
               #   i.e. ['3','7','9','2','4','3'] and 3 → [['3','7','9'],['2','4','3']]
               #   i.e. ['5','7','9','7','4','4'] and 3 → [['5','7','9'],['7','4','4']]
   J           #  Join each list together to a single number
               #   i.e. [['3','7','9'],['2','4','3']] → [379,243]
               #   i.e. [['5','7','9'],['7','4','4']] → [579,744]
    D          #  Duplicate this list
     O         #  Sum the list
               #   i.e. [379,243] → 622
               #   i.e. [579,744] → 1323
      ¹Q#      #  If it's equal to the first input: stop the infinite loop
               #  (and output the duplicate list implicitly)
               #   i.e. 1323 and 622 → 0 (falsey) → continue the loop
               #   i.e. 1323 and 1323 → 1 (truthy) → stop the loop and output [579,744]

Answer 8

Perl 6, 81 74 bytes

-7 bytes thanks to nwellnhof!

{first {try S/\=/==/.EVAL},map {$^a;S:g[\#]=$a[$++]},[X] ^10 xx.comb('#')}

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Anonymous code block that takes input as a string containing an arithmetical expression e.g. "12#+45#=579". Substitutes each # with possible permutations of digits, substitutes the= with == and finds the first valid result.

Explanation:

{  # Anonymous code block                                                      }
 first   # Find the first of:
                                                               ^10  # The range of 0 to 9
                                                                   xx.comb('#') # Multiplied by the number #s in the code
                                                          ,[X]  # The cross-product of these lists
                          map   # Map each crossproduct to:
                              {$^a;.trans: "#"=>{$a[$++]}}  # The given string with each # translated to each element in the list
      {try S/\=/==/.EVAL}, # Find which of these is true when = are changed to == and it is eval'd

Answer 9

APL (Dyalog Unicode), 22 bytes

{'#'⎕R{⍕?10}t}⍣{⍎⍺}t∘←

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Answer 10

Java 10, 203 198 193 bytes

(a,b,c)->{int A=0,B=0,l=a.length();for(a+=b,b="";A+B!=c;A=c.valueOf(b.substring(0,l)),B=c.valueOf(b.substring(l)),b="")for(var t:a.getBytes())b+=t<36?(t*=Math.random())%10:t-48;return A+"+"+B;}

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Explanation:

(a,b,c)->{           // Method with 2 Strings & integer parameters and String return-type
  int A=0,B=0,       //  Result-integers, starting both at 0
      l=a.length();  //  Length of the first String-input
  for(a+=b,          //  Concat the second String-input to the first
      b="";          //  Reuse `b`, and start it as an empty String
      A+B!=c         //  Loop as long as `A+B` isn't equal to the integer-input
      ;              //    After every iteration:
       A=c.valueOf(b.substring(0,l)),
                     //     Set `A` to the first String-part as integer
       B=c.valueOf(n.substring(l)),
                     //     Set `B` to the second String-part as integer
       b="")         //     Reset `b` to an empty String
    for(var t:a.getBytes())
                     //   Inner loop over the characters of the concatted String inputs
      b+=t<36?       //    If the current character is a '#':
          (t*=Math.random())%10
                     //     Append a random digit to `b`
         :           //    Else (it already is a digit):
          t-48;      //     Append this digit to `b`
  return A+"+"+B;}   //  After the loop, return `A` and `B` as result

Answer 11

C (gcc), 228 213 203 172 170 bytes

-15 Bytes thanks to @ceilingcat. I've never used index before.

-10 Bytes thanks to @Logem. Preprocessor magic

refactored call to exit(0) with puts as parameter.

char*c,*p[9],k;main(i,v)int**v;{for(i=X[1],35))||X[2],35))?p[k++]=c,main(*c=57,v):k;!c*i--;)47==--*p[i]?*p[i]=57:Y[1])+Y[2])^Y[3])?main(i,v):exit(puts(v[2],puts(v[1])));}

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Answer 12

Python 3, 121 155 152 149 bytes

import re
def f(i,k=0,S=re.sub):s=S('#','%s',i)%(*list('%0*d'%(i.count('#'),k)),);print(s)if eval(S('=','==',S('\\b0*([1-9])','\\1',s)))else f(i,k+1)

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+34 New solution with regex to circumvent the fact that python doesn't support numbers with leading zeroes.

-3 thanks to @Jonathan Frech

---

The old solution doesn't work if # is the first character in any number (because eval doesn't accept leading zeroes) and is therefore invalid :(

def f(i,k=0):
 s=i.replace('#','%s')%(*list('%0*d'%(i.count('#'),k)),)
 print(s)if eval(s.replace('=','=='))else f(i,k+1)

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Answer 13

C# .NET, 225 220 196 bytes

(a,b,c)=>{int A=0,B=0,l=a.Length;for(a+=b,b="";A+B!=c;A=int.Parse(b.Substring(0,l)),B=int.Parse(b.Substring(l)),b="")foreach(var t in a)b+=(t<36?new System.Random().Next(10):t-48)+"";return(A,B);}

Port of my Java 10 answer.
(I'm very rusty in C# .NET golfing, so can defintely be golfed..)

-3 bytes implicitly thanks to @user82593 and this new C# tip he added.
-29 bytes thanks to @hvd.

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Explanation:

(a,b,c)=>{        // Method with 2 string & int parameters and int-tuple return-type
  int A=0,B=0,    //  Result-integers, starting both at 0
      l=a.Length; //  Length of the first string-input
  for(a+=b,       //  Concat the second string-input to the first
      b="";       //  Reuse `b`, and start it as an empty string
      A+B!=c      //  Loop as long as `A+B` isn't equal to the integer-input
      ;           //    After every iteration:
       A=int.Parse(b.Substring(0,l)),
                  //     Set `A` to the first string-part as integer
       B=int.Parse(b.Substring(l)),
                  //     Set `B` to the second string-part as integer
       b="")      //     Reset `b` to an empty string
    foreach(var t in a)
                  //   Inner loop over the characters of the concatted string inputs
      b+=(t<36?   //    If the current character is a '#':
           new System.Random().Next(10)
                  //     Use a random digit
          :       //    Else (it already is a digit):
           t-48)  //     Use this digit as is
         +"";     //    And convert it to a string so it can be appended to the string
  return(A,B);}   //  After the loop, return `A` and `B` in a tuple as result

Answer 14

Powershell, 91 byte

The script finds all solutions. The total number of iterations is 10 power the number of characters #. The recursion depth is equal to the number of characters #.

filter f{$h,$t=$_-split'#',2
if($t){0..9|%{"$h$_$t"}|f}elseif($h-replace'=','-eq'|iex){$h}}

Test script:

filter f{$h,$t=$_-split'#',2
if($t){0..9|%{"$h$_$t"}|f}elseif($h-replace'=','-eq'|iex){$h}}

@(
    ,('1#3+45#=579','123+456=579')
    ,('#79+44#=1323','879+444=1323')
    ,('5#5+3#3=898','505+393=898 515+383=898 525+373=898 535+363=898 545+353=898 555+343=898 565+333=898 575+323=898 585+313=898 595+303=898')
    ,('#+#=2','0+2=2 1+1=2 2+0=2')
    ,('9+#6=55','9+46=55')
    ,('123+##=124','123+01=124')
    ,('#123651+#98#=1131632','1123651+7981=1131632')
    ,('##+##=2','00+02=2 01+01=2 02+00=2')
    ,('##+##=99','00+99=99 01+98=99 02+97=99 03+96=99 04+95=99 05+94=99 06+93=99 07+92=99 08+91=99 09+90=99 10+89=99 11+88=99 12+87=99 13+86=99 14+85=99 15+84=99 16+83=99 17+82=99 18+81=99 19+80=99 20+79=99 21+78=99 22+77=99 23+76=99 24+75=99 25+74=99 26+73=99 27+72=99 28+71=99 29+70=99 30+69=99 31+68=99 32+67=99 33+66=99 34+65=99 35+64=99 36+63=99 37+62=99 38+61=99 39+60=99 40+59=99 41+58=99 42+57=99 43+56=99 44+55=99 45+54=99 46+53=99 47+52=99 48+51=99 49+50=99 50+49=99 51+48=99 52+47=99 53+46=99 54+45=99 55+44=99 56+43=99 57+42=99 58+41=99 59+40=99 60+39=99 61+38=99 62+37=99 63+36=99 64+35=99 65+34=99 66+33=99 67+32=99 68+31=99 69+30=99 70+29=99 71+28=99 72+27=99 73+26=99 74+25=99 75+24=99 76+23=99 77+22=99 78+21=99 79+20=99 80+19=99 81+18=99 82+17=99 83+16=99 84+15=99 85+14=99 86+13=99 87+12=99 88+11=99 89+10=99 90+09=99 91+08=99 92+07=99 93+06=99 94+05=99 95+04=99 96+03=99 97+02=99 98+01=99 99+00=99')
) | % {
    $s,$e = $_
    $r = $s|f
    "$($e-eq$r): $r"
}

Powershell, 'Assume both term > 0' is mandatory, 110 bytes

filter f{$h,$t=$_-split'#',2
if($t){0..9|%{"$h$_$t"}|f}else{$a,$b,$c=$_-split'\D'
$_|?{+$a*+$b*!(+$a+$b-$c)}}}

Answer 15

PHP, 112 bytes

lame brute force solution

for(;$s=$argn;eval(strtr($s,['='=>'==','#'=>0]).'&&die($s);'))for($k=$n++;$k;$k=$k/10|0)$s[strpos($s,35)]=$k%10;

takes string as input, stops at first solution. Run as pipe with -nR or try it online.