Cubic Concatenation

Question

Challenge

Given three non-negative integers \$a, b\$ and \$c\$, decide if the sum of their cubes is equal to the concatenation of those numbers, aka: $$ a^{3}+b^{3}+c^{3} = a^\frown b ^\frown c $$

Test cases

Truthy

(1,5,3) // 1^3 + 5^3 + 3^3 = 153
(2,2,13)
(4,0,7)
(10,0,0)
(10,0,1)
(22,18,59)
(98,28,27)
(166,500,333)
(828,538,472)

Falsy

(1,2,3) // 1^3 + 2^3 + 3^3 = 32 != 123
(4,5,6)
(6,0,0)
(166,500,334)
(200,0,200)

You can assume there are no leading zeroes.

This is code-golf, so the shortest code wins.

Answer 1

Python 3, 36 bytes

lambda*I:eval(3*"%d"%I+3*"-%d**3"%I)

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eval golf of @Jitse's answer who generously declined to include it in their post. Returns zero for True and nonzero integer for False.

Answer 2

R, 30 29 bytes

Edit: -1 byte thanks to @Kirill L..

\(x)x^2%*%x==Reduce(paste0,x)

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Answer 3

Jelly,  5  4 bytes

-1 thanks to Unrelated String! (*3S {cube then sum} -> ḋ² {dot-product with squared values}.)

ḋ²⁼V

A monadic Link that accepts a list of non-negative integers (with or without any leading zeros^*) and yields 1 if the list concatenates to the sum of the cubes of its elements or 0 if not.

Try it online! Or see the test-suite.

How?

ḋ²⁼V - Link: list, A = [a, b, c]
 ²   - square {A} -> [a², b², c²]
ḋ    - {A} dot-product {that} -> a³+b³+c³
   V - evaluate {A} as Jelly code -> concatenated integer *
  ⁼  - {SumOfCubes} equals {that}?

^{* Leading zeros produce a side effect of printing zeros before yielding the result.}

Answer 4

Python 3, 44 bytes

lambda x:sum(map(pow,x,[3]*3))-int(3*'%d'%x)

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-1 byte thanks to Jonathan Allan

-2 bytes thanks to xnor

Returns truthy (nonzero integers) for False cases and falsey (zero integers) for True cases.

Python 3, 45 bytes

lambda a,b,c:a**3+b**3+c**3-int(f'{a}{b}{c}')

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Answer 5

Uiua, 17 14 12 chars

-3 chars thanks to Chunes by replacing fork with on

-2 chars thanks to OVS because I missed the existance of a power operator

=/+ⁿ3⟜⍜°⋕/⍚⊂

Pad Link

Answer 6

Haskell, 33 bytes

(==).show.sum.map(^3)<*>(>>=show)

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• sum.map(^3) is the sum of the cubes
• show.sum.map(^3) is stringifies the sum
• (>>=show) is concatMap show, i.e. concatenetes the numbers
• <*> feeds the input to both arguments

Answer 7

Vyxal, 6 bytes

ṅ?3e∑=

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    ∑  # Sum
  3e   # of cubes
 ?     # of input
     = # Is equal to
ṅ      # Concatenation of input?

Answer 8

APL (Dyalog Unicode), 16 bytes

+.*∘3=∘⍎∘∊⍕¨

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+.*∘3 sum of cubes

=∘⍎∘∊ equal to the execution of the enlisted (flattened)

⍕¨ stringification of each

Answer 9

JavaScript (Node.js), 32 bytes

(a,b,c)=>a**3+b**3+c**3==[a]+b+c

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Nothing to say.

Answer 10

Julia, 26 24 23 bytes

-n="$(n'n.^2)"==join(n)

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Thanks to ovs for -2 and further -1 by Ashlin Harris.

Answer 11

K (ngn/k), 17 bytes

{(,/$x)~$+/x*x*x}

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Answer 12

Google Sheets, 31 bytes

=SUMPRODUCT(A:A^3)=--JOIN(,A:A) 

Answer 13

Brachylog, 7 bytes

^₃ᵐ+~c?

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Explanation

^₃ᵐ        Map cube on the input list
   +       The sum of these cubes…
    ~c?    …can be deconcatenated into the original input list

Answer 14

Bash, 28

Sometimes the simple solution is best:

(($1**3+$2**3+$3**3^$1$2$3))

This script takes a list as command-line parameters as input. e.g. ./cubeconcat.sh 1 5 3. It returns a shell exit code: 1 for True, 0 for False.

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---

Previous, overcomplicated solution:

Bash, 37

(($(eval printf %s +\$[$1**3] ^ $1)))

This script takes a single quoted brace-enclosed, comma-separated list as input. e.g. ./cubeconcat.sh "{1,5,3}". It returns a shell exit code: 1 for True, 0 for False.

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Answer 15

Desmos, 81 67 bytes

-14 bytes thanks to @emanresu A due to the fact that I didn't realize that it was always guaranteed to be exactly 3 numerical inputs. I was originally solving for an arbitrary amount of numerical inputs.

c(x,y)=x10^{floor(log(y+0^y))+1}+y
f(x,y,z)=c(c(x,y),z)-x^3-y^3-z^3

Returns 0 for truthy and a non-zero integer for falsey.

Try It On Desmos!

Try It On Desmos! - Prettified

Answer 16

Excel, 23 Bytes

An anonymous workbook function that takes input from a vertical array at A1# and outputs to the calling cell

--(A1&A2&A3)=SUM(A1#^3)

Previous Version, 24 bytes

A slightly more elegant solution that uses the Concat builtin

--CONCAT(A1#)=SUM(A1#^3)

Sample Output

For the input array ={1;5;3} outputs the following

Answer 17

Perl 5 -MList::Util=sum -ap, 27 bytes

$_=y/ //dr==sum map$_**3,@F

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Answer 18

Red, 41 bytes

func[a][(sum a * a * a)= do rejoin to[]a]

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Takes input as a vector of three numbers. Vectors support arithmetic with multiple values at once, but not powers.

Explanation

func[a][         ; start function taking argument a
(sum a * a * a)  ; sum of cubes
=                ; does it equal...
to[]a            ; input converted to regular list
rejoin           ; concatenated to string
do               ; evaluated (converted to integer)
]                ; end function

Answer 19

Stack control 1.1, 6 characters

:³+⇆◡=

Explanation

:  - duplicates original array
³  - cubes every array element
+  - sum of array elements
⇆  - swap to another array
◡  - reversed concatenates values from array
=  - check if values are equals

Answer 20

Javascript (V8), 40 bytes

a=>a.reduce((x,y)=>x+y**3,0)==a.join('')

where a is number[], so it should work for any number of arguments.

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33 bytes

Thanks @Neil and @tsh for the shorter version!

a=>a.map(x=>s-=x**3,s=a.join``)|s

Answer 21

MathGolf, 5 bytes

‼yⁿΣ=

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Explanation:

‼     # Apply the next two operands separately on the (implicit) input-triplet:
 y    #  Join them together
  ⁿ   #  Take the cube of each
   Σ  # Sum the triplet of cubes
    = # Check if the two lists are the same
      # (after which the entire stack joined together is output implicitly)

Answer 22

Japt, 5 bytes

x³¥U¬

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x³¥U¬     :Implicit input of array U
x         :Sum of
 ³        :  Cubes
  ¥       :Loosely equal to
   U¬     :  U joined to a string

Answer 23

ARBLE, 21 bytes

a^3+b^3+c^3-(a..b..c)

0 for truthy, non-zero for falsey.

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Run all tests!

Answer 24

APL+WIN, 17 bytes

Prompts for integers.

(⍎∊⍕¨s)=+/(s←⎕)*3

Try it online! Thanks to Dyalog Classic

Answer 25

Arturo, 31 bytes

$->a->=do join a∑map a=>[&^3]

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Explanation

$->a->        ; a function taking a list named a
=             ; are the following two values equal?
do join a     ; concatenation of input as a number
∑             ; and sum of...
map a=>[&^3]  ; inputs cubed

Answer 26

Setanta, 84 66 bytes

gniomh(a,b,c){toradh a*a*a+b*b*b+c*c*c==go_uimh(nasc@[a,b,c](""))}

try-setanta.ie link

Answer 27

Kotlin 52 Bytes

{it.map{it*it*it}.sum()-it.joinToString("").toInt()}

Accepts a List<Int> and outputs zero for true and a non-zero integer for false.

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Answer 28

C++, 186 165 146 bytes

#include<iostream>
using namespace std;int main(){int a,b,c;cin>>a>>b>>c;cout<<(a*a*a+b*b*b+c*c*c==stoi(to_string(a)+to_string(b)+to_string(c)));}

(-16 thanks to Mousetail) (-19 thanks to Blue)

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Answer 29

Windows Batch, 43 bytes

cmd/cset/a%1*%1*%1+%2*%2*%2+%3*%3*%3-%1%2%3

Prints 0 for truthy, <>0 for falsy.

Sorry, no TIO available; save as C:\Temp\cg274690.cmd or whatever.cmd, run from cmd.exe or PowerShell:
C:\Temp\cg274690.cmd 1 5 3

Ungolfed:

cmd.exe /c set /a %1 * %1 * %1 + %2 * %2 * %2 + %3 * %3 * %3 - %1%2%3

This starts another instance of cmd.exe, as using set /a inside a batch script requires an assignment, which would then have to be echoed out, for a total of 49 bytes (using LF as EOL):

set/ax=%1*%1*%1+%2*%2*%2+%3*%3*%3-%1%2%3
echo %x%

set /a used interactively inside a cmd prompt (or passed with /c) prints the result directly.

Answer 30

Ruby, 30 bytes

->a{a.sum{|x|x**3}.to_s==a*''}

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