A Note on N!Pseudo-cyclic Number EvaluatorFind the remaining side of the tangential quadrilateralSelf Referential PolynomialsClosest Woodall PrimeTriple-balanced numbersprepend,append-SequenceReconstruct an arithmetic sequenceFour Spiraling AxesExact Partial Sum of Harmonic SeriesRyley's Theorem
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A Note on N!
Pseudo-cyclic Number EvaluatorFind the remaining side of the tangential quadrilateralSelf Referential PolynomialsClosest Woodall PrimeTriple-balanced numbersprepend,append-SequenceReconstruct an arithmetic sequenceFour Spiraling AxesExact Partial Sum of Harmonic SeriesRyley's Theorem
$begingroup$
J. E. Maxfield proved following theorem (see DOI: 10.2307/2688966):
If A is any positive integer having m digits, there exists a positive integer N such that the first m digits of N! constitute the integer A.
Challenge
Your challenge is given some A
find a corresponding N
(in base 10).
Details
- Your submission should work for arbitrary
A
given enough time and memory. Just using e.g. 32-bit types to represent integers is not sufficient. - You don't necessarily need to output the least possible
N
.
Examples
A N
1 1
2 2
3 9
4 8
5 7
6 3
7 6
9 96
12 5
16 89
17 69
18 76
19 63
24 4
72 6
841 12745
206591378 314
The least possible N
for each A
can be found in https://oeis.org/A076219
code-golf math number integer factorial
$endgroup$
|
show 3 more comments
$begingroup$
J. E. Maxfield proved following theorem (see DOI: 10.2307/2688966):
If A is any positive integer having m digits, there exists a positive integer N such that the first m digits of N! constitute the integer A.
Challenge
Your challenge is given some A
find a corresponding N
(in base 10).
Details
- Your submission should work for arbitrary
A
given enough time and memory. Just using e.g. 32-bit types to represent integers is not sufficient. - You don't necessarily need to output the least possible
N
.
Examples
A N
1 1
2 2
3 9
4 8
5 7
6 3
7 6
9 96
12 5
16 89
17 69
18 76
19 63
24 4
72 6
841 12745
206591378 314
The least possible N
for each A
can be found in https://oeis.org/A076219
code-golf math number integer factorial
$endgroup$
5
$begingroup$
I... why did he prove that theorem? Did he just wake up one day and say "I shall solve this!" or did it serve a purpose?
$endgroup$
– Magic Octopus Urn
7 hours ago
$begingroup$
By "any A" do you mean that like using numbers in Python orlong long
s in C++ is invalid?
$endgroup$
– HyperNeutrino
6 hours ago
2
$begingroup$
Can we return0
for input1
? Lynn's answer currently does.
$endgroup$
– Erik the Outgolfer
6 hours ago
2
$begingroup$
@SolomonUcko My question is whether we're actually required to output a positive integer or not, though, that quote itself isn't really enough to specify that, and nowhere does it say that the test cases include the least possible output for each input.
$endgroup$
– Erik the Outgolfer
5 hours ago
1
$begingroup$
@SolomonUcko Yes, "positive" excludes 0, but, again, nowhere in the challenge does it say that the output must be positive. Well, technically, it does restrict the output, but you really need to see into the details to figure that out (the challenge text also uses the "N" variable), so it's not at all clear if OP actually intended to restrict the output to the positive integers or if we can output0
for input1
as well.
$endgroup$
– Erik the Outgolfer
5 hours ago
|
show 3 more comments
$begingroup$
J. E. Maxfield proved following theorem (see DOI: 10.2307/2688966):
If A is any positive integer having m digits, there exists a positive integer N such that the first m digits of N! constitute the integer A.
Challenge
Your challenge is given some A
find a corresponding N
(in base 10).
Details
- Your submission should work for arbitrary
A
given enough time and memory. Just using e.g. 32-bit types to represent integers is not sufficient. - You don't necessarily need to output the least possible
N
.
Examples
A N
1 1
2 2
3 9
4 8
5 7
6 3
7 6
9 96
12 5
16 89
17 69
18 76
19 63
24 4
72 6
841 12745
206591378 314
The least possible N
for each A
can be found in https://oeis.org/A076219
code-golf math number integer factorial
$endgroup$
J. E. Maxfield proved following theorem (see DOI: 10.2307/2688966):
If A is any positive integer having m digits, there exists a positive integer N such that the first m digits of N! constitute the integer A.
Challenge
Your challenge is given some A
find a corresponding N
(in base 10).
Details
- Your submission should work for arbitrary
A
given enough time and memory. Just using e.g. 32-bit types to represent integers is not sufficient. - You don't necessarily need to output the least possible
N
.
Examples
A N
1 1
2 2
3 9
4 8
5 7
6 3
7 6
9 96
12 5
16 89
17 69
18 76
19 63
24 4
72 6
841 12745
206591378 314
The least possible N
for each A
can be found in https://oeis.org/A076219
code-golf math number integer factorial
code-golf math number integer factorial
asked 7 hours ago
flawrflawr
27.5k668194
27.5k668194
5
$begingroup$
I... why did he prove that theorem? Did he just wake up one day and say "I shall solve this!" or did it serve a purpose?
$endgroup$
– Magic Octopus Urn
7 hours ago
$begingroup$
By "any A" do you mean that like using numbers in Python orlong long
s in C++ is invalid?
$endgroup$
– HyperNeutrino
6 hours ago
2
$begingroup$
Can we return0
for input1
? Lynn's answer currently does.
$endgroup$
– Erik the Outgolfer
6 hours ago
2
$begingroup$
@SolomonUcko My question is whether we're actually required to output a positive integer or not, though, that quote itself isn't really enough to specify that, and nowhere does it say that the test cases include the least possible output for each input.
$endgroup$
– Erik the Outgolfer
5 hours ago
1
$begingroup$
@SolomonUcko Yes, "positive" excludes 0, but, again, nowhere in the challenge does it say that the output must be positive. Well, technically, it does restrict the output, but you really need to see into the details to figure that out (the challenge text also uses the "N" variable), so it's not at all clear if OP actually intended to restrict the output to the positive integers or if we can output0
for input1
as well.
$endgroup$
– Erik the Outgolfer
5 hours ago
|
show 3 more comments
5
$begingroup$
I... why did he prove that theorem? Did he just wake up one day and say "I shall solve this!" or did it serve a purpose?
$endgroup$
– Magic Octopus Urn
7 hours ago
$begingroup$
By "any A" do you mean that like using numbers in Python orlong long
s in C++ is invalid?
$endgroup$
– HyperNeutrino
6 hours ago
2
$begingroup$
Can we return0
for input1
? Lynn's answer currently does.
$endgroup$
– Erik the Outgolfer
6 hours ago
2
$begingroup$
@SolomonUcko My question is whether we're actually required to output a positive integer or not, though, that quote itself isn't really enough to specify that, and nowhere does it say that the test cases include the least possible output for each input.
$endgroup$
– Erik the Outgolfer
5 hours ago
1
$begingroup$
@SolomonUcko Yes, "positive" excludes 0, but, again, nowhere in the challenge does it say that the output must be positive. Well, technically, it does restrict the output, but you really need to see into the details to figure that out (the challenge text also uses the "N" variable), so it's not at all clear if OP actually intended to restrict the output to the positive integers or if we can output0
for input1
as well.
$endgroup$
– Erik the Outgolfer
5 hours ago
5
5
$begingroup$
I... why did he prove that theorem? Did he just wake up one day and say "I shall solve this!" or did it serve a purpose?
$endgroup$
– Magic Octopus Urn
7 hours ago
$begingroup$
I... why did he prove that theorem? Did he just wake up one day and say "I shall solve this!" or did it serve a purpose?
$endgroup$
– Magic Octopus Urn
7 hours ago
$begingroup$
By "any A" do you mean that like using numbers in Python or
long long
s in C++ is invalid?$endgroup$
– HyperNeutrino
6 hours ago
$begingroup$
By "any A" do you mean that like using numbers in Python or
long long
s in C++ is invalid?$endgroup$
– HyperNeutrino
6 hours ago
2
2
$begingroup$
Can we return
0
for input 1
? Lynn's answer currently does.$endgroup$
– Erik the Outgolfer
6 hours ago
$begingroup$
Can we return
0
for input 1
? Lynn's answer currently does.$endgroup$
– Erik the Outgolfer
6 hours ago
2
2
$begingroup$
@SolomonUcko My question is whether we're actually required to output a positive integer or not, though, that quote itself isn't really enough to specify that, and nowhere does it say that the test cases include the least possible output for each input.
$endgroup$
– Erik the Outgolfer
5 hours ago
$begingroup$
@SolomonUcko My question is whether we're actually required to output a positive integer or not, though, that quote itself isn't really enough to specify that, and nowhere does it say that the test cases include the least possible output for each input.
$endgroup$
– Erik the Outgolfer
5 hours ago
1
1
$begingroup$
@SolomonUcko Yes, "positive" excludes 0, but, again, nowhere in the challenge does it say that the output must be positive. Well, technically, it does restrict the output, but you really need to see into the details to figure that out (the challenge text also uses the "N" variable), so it's not at all clear if OP actually intended to restrict the output to the positive integers or if we can output
0
for input 1
as well.$endgroup$
– Erik the Outgolfer
5 hours ago
$begingroup$
@SolomonUcko Yes, "positive" excludes 0, but, again, nowhere in the challenge does it say that the output must be positive. Well, technically, it does restrict the output, but you really need to see into the details to figure that out (the challenge text also uses the "N" variable), so it's not at all clear if OP actually intended to restrict the output to the positive integers or if we can output
0
for input 1
as well.$endgroup$
– Erik the Outgolfer
5 hours ago
|
show 3 more comments
12 Answers
12
active
oldest
votes
$begingroup$
Python 2, 47 bytes
f=lambda a,n=1,p=1:`p`.find(a)and-~f(a,n+1,p*n)
Try it online!
Takes a string as input, like f('18')
.
The trick here is that x.find(y) == 0
precisely when x.startswith(y)
.
The and
-expression will short circuit at `p`.find(a)
with result 0
as soon as `p`
starts with a
; otherwise, it will evaluate to -~f(a,n+1,p*n)
, id est 1 + f(a,n+1,p*n)
.
The end result is 1 + (1 + (1 + (... + 0)))
, n
layers deep, so n
.
$endgroup$
1
$begingroup$
Returns0
for1
.
$endgroup$
– Shaggy
6 hours ago
2
$begingroup$
@Shaggy I've asked about that in the comments, because0
is a pretty sensible answer if it must just be non-negative (a fix could cost up to 8 bytes).
$endgroup$
– Erik the Outgolfer
6 hours ago
1
$begingroup$
@EriktheOutgolfer hmm, I can think off=lambda a,n=2,p=1:(`p`.find(a)and f(a,n+1,p*n))+1
, a +3 byte fix.
$endgroup$
– Lynn
6 hours ago
$begingroup$
@Lynn Maybe, I'm a bit tired now. :P
$endgroup$
– Erik the Outgolfer
6 hours ago
$begingroup$
Nice solution by the way. I was working on the same method but calculating the factorial on each iteration; implementing your approach saved me a few bytes so+1
anyway.
$endgroup$
– Shaggy
6 hours ago
|
show 1 more comment
$begingroup$
Jelly, 8 bytes
1!w⁼1ʋ1#
Try it online!
Takes an integer and returns a singleton.
$endgroup$
add a comment |
$begingroup$
JavaScript, 47 43 bytes
I/O as a BigInt.
n=>(g=x=>`$x`.search(n)?g(x*++i):i)(i=1n)
Try It Online (The 841
test case times out on TIO)
Saved a few bytes by taking Lynn's approach of "building" the factorial rather than calculating it on each iteration so please upvote her solution as well if you're upvoting this one.
$endgroup$
$begingroup$
Sadly,_Ês bU}f1
in Japt doesn't work
$endgroup$
– Embodiment of Ignorance
6 hours ago
$begingroup$
@EmbodimentofIgnorance, yeah, I had that too. You could remove the space afters
.
$endgroup$
– Shaggy
6 hours ago
$begingroup$
@EmbodimentofIgnorance, you could also remove the1
if0
can be returned forn=1
.
$endgroup$
– Shaggy
5 hours ago
add a comment |
$begingroup$
Jelly, 16 bytes
‘ɼ!³;D®ß⁼Lḣ@¥¥/?
Try it online!
Explanation
‘ɼ | Increment the register (initially 0)
! | Factorial
³; | Prepend the input
D | Convert to decimal digits
⁼ ¥¥/? | If the input diguts are equal to...
Lḣ@ | The same number of diguts from the head of the factorial
® | Return the register
ß | Otherwise run the link again
$endgroup$
add a comment |
$begingroup$
Jelly, 11 bytes
‘ɼµ®!Dw³’µ¿
Try it online!
$endgroup$
add a comment |
$begingroup$
Pyth - 8 bytes
f!x`.!Tz
f filter. With no second arg, it searches 1.. for first truthy
! logical not, here it checks for zero
x z indexof. z is input as string
` string repr
.!T Factorial of lambda var
Try it online.
$endgroup$
add a comment |
$begingroup$
Perl 6, 23 bytes
+([*](1..*).../^$_/)
Try it online!
Explanation
# Anonymous code block
[*](1..*) # From the infinite list of factorials
... # Take up to the first element
/^$_/ # That starts with the input
+( ) # And return the length of the sequence
$endgroup$
add a comment |
$begingroup$
Charcoal, 16 bytes
⊞υ¹W⌕IΠυθ⊞υLυI⊟υ
Try it online! Link is to verbose version of code. Explanation:
⊞υ¹
Push 1
to the empty list so that it starts off with a defined product.
W⌕IΠυθ
Repeat while the input cannot be found at the beginning of the product of the list...
⊞υLυ
... push the length of the list to itself.
I⊟υ
Print the last value pushed to the list.
$endgroup$
add a comment |
$begingroup$
Perl 5 -Mbigint -p
, 25 bytes
1while($.*=++$)!~/^$_/}improve this answer
$begingroup$
@EmbodimentofIgnorance, yeah, I had that too. You could remove the space after
s
.$endgroup$
– Shaggy
6 hours ago
$begingroup$
@EmbodimentofIgnorance, you could also remove the
1
if 0
can be returned for n=1
.$endgroup$
– Shaggy
5 hours ago
add a comment |
$begingroup$
JavaScript, 47 43 bytes
I/O as a BigInt.
n=>(g=x=>`$x`.search(n)?g(x*++i):i)(i=1n)
Try It Online (The 841
test case times out on TIO)
Saved a few bytes by taking Lynn's approach of "building" the factorial rather than calculating it on each iteration so please upvote her solution as well if you're upvoting this one.
$endgroup$
$begingroup$
Sadly,_Ês bU}f1
in Japt doesn't work
$endgroup$
– Embodiment of Ignorance
6 hours ago
$begingroup$
@EmbodimentofIgnorance, yeah, I had that too. You could remove the space afters
.
$endgroup$
– Shaggy
6 hours ago
$begingroup$
@EmbodimentofIgnorance, you could also remove the1
if0
can be returned forn=1
.
$endgroup$
– Shaggy
5 hours ago
add a comment |
$begingroup$
JavaScript, 47 43 bytes
I/O as a BigInt.
n=>(g=x=>`$x`.search(n)?g(x*++i):i)(i=1n)
Try It Online (The 841
test case times out on TIO)
Saved a few bytes by taking Lynn's approach of "building" the factorial rather than calculating it on each iteration so please upvote her solution as well if you're upvoting this one.
$endgroup$
JavaScript, 47 43 bytes
I/O as a BigInt.
n=>(g=x=>`$x`.search(n)?g(x*++i):i)(i=1n)
Try It Online (The 841
test case times out on TIO)
Saved a few bytes by taking Lynn's approach of "building" the factorial rather than calculating it on each iteration so please upvote her solution as well if you're upvoting this one.
edited 5 hours ago
answered 6 hours ago
ShaggyShaggy
19.2k21768
19.2k21768
$begingroup$
Sadly,_Ês bU}f1
in Japt doesn't work
$endgroup$
– Embodiment of Ignorance
6 hours ago
$begingroup$
@EmbodimentofIgnorance, yeah, I had that too. You could remove the space afters
.
$endgroup$
– Shaggy
6 hours ago
$begingroup$
@EmbodimentofIgnorance, you could also remove the1
if0
can be returned forn=1
.
$endgroup$
– Shaggy
5 hours ago
add a comment |
$begingroup$
Sadly,_Ês bU}f1
in Japt doesn't work
$endgroup$
– Embodiment of Ignorance
6 hours ago
$begingroup$
@EmbodimentofIgnorance, yeah, I had that too. You could remove the space afters
.
$endgroup$
– Shaggy
6 hours ago
$begingroup$
@EmbodimentofIgnorance, you could also remove the1
if0
can be returned forn=1
.
$endgroup$
– Shaggy
5 hours ago
$begingroup$
Sadly,
_Ês bU}f1
in Japt doesn't work$endgroup$
– Embodiment of Ignorance
6 hours ago
$begingroup$
Sadly,
_Ês bU}f1
in Japt doesn't work$endgroup$
– Embodiment of Ignorance
6 hours ago
$begingroup$
@EmbodimentofIgnorance, yeah, I had that too. You could remove the space after
s
.$endgroup$
– Shaggy
6 hours ago
$begingroup$
@EmbodimentofIgnorance, yeah, I had that too. You could remove the space after
s
.$endgroup$
– Shaggy
6 hours ago
$begingroup$
@EmbodimentofIgnorance, you could also remove the
1
if 0
can be returned for n=1
.$endgroup$
– Shaggy
5 hours ago
$begingroup$
@EmbodimentofIgnorance, you could also remove the
1
if 0
can be returned for n=1
.$endgroup$
– Shaggy
5 hours ago
add a comment |
$begingroup$
Jelly, 16 bytes
‘ɼ!³;D®ß⁼Lḣ@¥¥/?
Try it online!
Explanation
‘ɼ | Increment the register (initially 0)
! | Factorial
³; | Prepend the input
D | Convert to decimal digits
⁼ ¥¥/? | If the input diguts are equal to...
Lḣ@ | The same number of diguts from the head of the factorial
® | Return the register
ß | Otherwise run the link again
$endgroup$
add a comment |
$begingroup$
Jelly, 16 bytes
‘ɼ!³;D®ß⁼Lḣ@¥¥/?
Try it online!
Explanation
‘ɼ | Increment the register (initially 0)
! | Factorial
³; | Prepend the input
D | Convert to decimal digits
⁼ ¥¥/? | If the input diguts are equal to...
Lḣ@ | The same number of diguts from the head of the factorial
® | Return the register
ß | Otherwise run the link again
$endgroup$
add a comment |
$begingroup$
Jelly, 16 bytes
‘ɼ!³;D®ß⁼Lḣ@¥¥/?
Try it online!
Explanation
‘ɼ | Increment the register (initially 0)
! | Factorial
³; | Prepend the input
D | Convert to decimal digits
⁼ ¥¥/? | If the input diguts are equal to...
Lḣ@ | The same number of diguts from the head of the factorial
® | Return the register
ß | Otherwise run the link again
$endgroup$
Jelly, 16 bytes
‘ɼ!³;D®ß⁼Lḣ@¥¥/?
Try it online!
Explanation
‘ɼ | Increment the register (initially 0)
! | Factorial
³; | Prepend the input
D | Convert to decimal digits
⁼ ¥¥/? | If the input diguts are equal to...
Lḣ@ | The same number of diguts from the head of the factorial
® | Return the register
ß | Otherwise run the link again
edited 6 hours ago
answered 6 hours ago
Nick KennedyNick Kennedy
1,91149
1,91149
add a comment |
add a comment |
$begingroup$
Jelly, 11 bytes
‘ɼµ®!Dw³’µ¿
Try it online!
$endgroup$
add a comment |
$begingroup$
Jelly, 11 bytes
‘ɼµ®!Dw³’µ¿
Try it online!
$endgroup$
add a comment |
$begingroup$
Jelly, 11 bytes
‘ɼµ®!Dw³’µ¿
Try it online!
$endgroup$
Jelly, 11 bytes
‘ɼµ®!Dw³’µ¿
Try it online!
edited 6 hours ago
answered 6 hours ago
HyperNeutrinoHyperNeutrino
19.1k437148
19.1k437148
add a comment |
add a comment |
$begingroup$
Pyth - 8 bytes
f!x`.!Tz
f filter. With no second arg, it searches 1.. for first truthy
! logical not, here it checks for zero
x z indexof. z is input as string
` string repr
.!T Factorial of lambda var
Try it online.
$endgroup$
add a comment |
$begingroup$
Pyth - 8 bytes
f!x`.!Tz
f filter. With no second arg, it searches 1.. for first truthy
! logical not, here it checks for zero
x z indexof. z is input as string
` string repr
.!T Factorial of lambda var
Try it online.
$endgroup$
add a comment |
$begingroup$
Pyth - 8 bytes
f!x`.!Tz
f filter. With no second arg, it searches 1.. for first truthy
! logical not, here it checks for zero
x z indexof. z is input as string
` string repr
.!T Factorial of lambda var
Try it online.
$endgroup$
Pyth - 8 bytes
f!x`.!Tz
f filter. With no second arg, it searches 1.. for first truthy
! logical not, here it checks for zero
x z indexof. z is input as string
` string repr
.!T Factorial of lambda var
Try it online.
answered 5 hours ago
MaltysenMaltysen
21.5k445117
21.5k445117
add a comment |
add a comment |
$begingroup$
Perl 6, 23 bytes
+([*](1..*).../^$_/)
Try it online!
Explanation
# Anonymous code block
[*](1..*) # From the infinite list of factorials
... # Take up to the first element
/^$_/ # That starts with the input
+( ) # And return the length of the sequence
$endgroup$
add a comment |
$begingroup$
Perl 6, 23 bytes
+([*](1..*).../^$_/)
Try it online!
Explanation
# Anonymous code block
[*](1..*) # From the infinite list of factorials
... # Take up to the first element
/^$_/ # That starts with the input
+( ) # And return the length of the sequence
$endgroup$
add a comment |
$begingroup$
Perl 6, 23 bytes
+([*](1..*).../^$_/)
Try it online!
Explanation
# Anonymous code block
[*](1..*) # From the infinite list of factorials
... # Take up to the first element
/^$_/ # That starts with the input
+( ) # And return the length of the sequence
$endgroup$
Perl 6, 23 bytes
+([*](1..*).../^$_/)
Try it online!
Explanation
# Anonymous code block
[*](1..*) # From the infinite list of factorials
... # Take up to the first element
/^$_/ # That starts with the input
+( ) # And return the length of the sequence
answered 5 hours ago
Jo KingJo King
27.6k366133
27.6k366133
add a comment |
add a comment |
$begingroup$
Charcoal, 16 bytes
⊞υ¹W⌕IΠυθ⊞υLυI⊟υ
Try it online! Link is to verbose version of code. Explanation:
⊞υ¹
Push 1
to the empty list so that it starts off with a defined product.
W⌕IΠυθ
Repeat while the input cannot be found at the beginning of the product of the list...
⊞υLυ
... push the length of the list to itself.
I⊟υ
Print the last value pushed to the list.
$endgroup$
add a comment |
$begingroup$
Charcoal, 16 bytes
⊞υ¹W⌕IΠυθ⊞υLυI⊟υ
Try it online! Link is to verbose version of code. Explanation:
⊞υ¹
Push 1
to the empty list so that it starts off with a defined product.
W⌕IΠυθ
Repeat while the input cannot be found at the beginning of the product of the list...
⊞υLυ
... push the length of the list to itself.
I⊟υ
Print the last value pushed to the list.
$endgroup$
add a comment |
$begingroup$
Charcoal, 16 bytes
⊞υ¹W⌕IΠυθ⊞υLυI⊟υ
Try it online! Link is to verbose version of code. Explanation:
⊞υ¹
Push 1
to the empty list so that it starts off with a defined product.
W⌕IΠυθ
Repeat while the input cannot be found at the beginning of the product of the list...
⊞υLυ
... push the length of the list to itself.
I⊟υ
Print the last value pushed to the list.
$endgroup$
Charcoal, 16 bytes
⊞υ¹W⌕IΠυθ⊞υLυI⊟υ
Try it online! Link is to verbose version of code. Explanation:
⊞υ¹
Push 1
to the empty list so that it starts off with a defined product.
W⌕IΠυθ
Repeat while the input cannot be found at the beginning of the product of the list...
⊞υLυ
... push the length of the list to itself.
I⊟υ
Print the last value pushed to the list.
answered 4 hours ago
NeilNeil
83.3k745179
83.3k745179
add a comment |
add a comment |
$begingroup$
Perl 5 -Mbigint -p
, 25 bytes
1while($.*=++$)!~/^$_/}
$begingroup$
Perl 5 -Mbigint -p
, 25 bytes
1while($.*=++$)!~/^$_/
Try it online!
answered 4 hours ago
XcaliXcali
5,585521
5,585521
add a comment |
add a comment |
$begingroup$
Clean, 88 bytes
import StdEnv,Data.Integer,Text
$a=hd[n\n<-[a/a..]|startsWith(""<+a)(""<+prod[one..n])]
Try it online!
Defines $ :: Integer -> Integer
.
Uses Data.Integer
's arbitrary size integers for IO.
$endgroup$
add a comment |
$begingroup$
Clean, 88 bytes
import StdEnv,Data.Integer,Text
$a=hd[n\n<-[a/a..]|startsWith(""<+a)(""<+prod[one..n])]
Try it online!
Defines $ :: Integer -> Integer
.
Uses Data.Integer
's arbitrary size integers for IO.
$endgroup$
add a comment |
$begingroup$
Clean, 88 bytes
import StdEnv,Data.Integer,Text
$a=hd[n\n<-[a/a..]|startsWith(""<+a)(""<+prod[one..n])]
Try it online!
Defines $ :: Integer -> Integer
.
Uses Data.Integer
's arbitrary size integers for IO.
$endgroup$
Clean, 88 bytes
import StdEnv,Data.Integer,Text
$a=hd[n\n<-[a/a..]|startsWith(""<+a)(""<+prod[one..n])]
Try it online!
Defines $ :: Integer -> Integer
.
Uses Data.Integer
's arbitrary size integers for IO.
answered 3 hours ago
ΟurousΟurous
7,41611136
7,41611136
add a comment |
add a comment |
$begingroup$
Wolfram Language (Mathematica), 62 bytes
(b=1;While[⌊b!/10^((i=IntegerLength)[b!]-i@#)⌋!=#,b++];b)&
Try it online!
$endgroup$
add a comment |
$begingroup$
Wolfram Language (Mathematica), 62 bytes
(b=1;While[⌊b!/10^((i=IntegerLength)[b!]-i@#)⌋!=#,b++];b)&
Try it online!
$endgroup$
add a comment |
$begingroup$
Wolfram Language (Mathematica), 62 bytes
(b=1;While[⌊b!/10^((i=IntegerLength)[b!]-i@#)⌋!=#,b++];b)&
Try it online!
$endgroup$
Wolfram Language (Mathematica), 62 bytes
(b=1;While[⌊b!/10^((i=IntegerLength)[b!]-i@#)⌋!=#,b++];b)&
Try it online!
edited 2 hours ago
answered 2 hours ago
J42161217J42161217
14.5k21354
14.5k21354
add a comment |
add a comment |
$begingroup$
Python 3, 64 bytes
lambda x,a=2,b=1:str(b).startswith(str(x))and a-1or f(x,a+1,b*a)
Try it online!
-24 bytes thanks to Jo King
$endgroup$
$begingroup$
64 bytes
$endgroup$
– Jo King
5 hours ago
$begingroup$
@JoKing nice, thanks
$endgroup$
– HyperNeutrino
2 hours ago
add a comment |
$begingroup$
Python 3, 64 bytes
lambda x,a=2,b=1:str(b).startswith(str(x))and a-1or f(x,a+1,b*a)
Try it online!
-24 bytes thanks to Jo King
$endgroup$
$begingroup$
64 bytes
$endgroup$
– Jo King
5 hours ago
$begingroup$
@JoKing nice, thanks
$endgroup$
– HyperNeutrino
2 hours ago
add a comment |
$begingroup$
Python 3, 64 bytes
lambda x,a=2,b=1:str(b).startswith(str(x))and a-1or f(x,a+1,b*a)
Try it online!
-24 bytes thanks to Jo King
$endgroup$
Python 3, 64 bytes
lambda x,a=2,b=1:str(b).startswith(str(x))and a-1or f(x,a+1,b*a)
Try it online!
-24 bytes thanks to Jo King
edited 2 hours ago
answered 7 hours ago
HyperNeutrinoHyperNeutrino
19.1k437148
19.1k437148
$begingroup$
64 bytes
$endgroup$
– Jo King
5 hours ago
$begingroup$
@JoKing nice, thanks
$endgroup$
– HyperNeutrino
2 hours ago
add a comment |
$begingroup$
64 bytes
$endgroup$
– Jo King
5 hours ago
$begingroup$
@JoKing nice, thanks
$endgroup$
– HyperNeutrino
2 hours ago
$begingroup$
64 bytes
$endgroup$
– Jo King
5 hours ago
$begingroup$
64 bytes
$endgroup$
– Jo King
5 hours ago
$begingroup$
@JoKing nice, thanks
$endgroup$
– HyperNeutrino
2 hours ago
$begingroup$
@JoKing nice, thanks
$endgroup$
– HyperNeutrino
2 hours ago
add a comment |
If this is an answer to a challenge…
…Be sure to follow the challenge specification. However, please refrain from exploiting obvious loopholes. Answers abusing any of the standard loopholes are considered invalid. If you think a specification is unclear or underspecified, comment on the question instead.
…Try to optimize your score. For instance, answers to code-golf challenges should attempt to be as short as possible. You can always include a readable version of the code in addition to the competitive one.
Explanations of your answer make it more interesting to read and are very much encouraged.…Include a short header which indicates the language(s) of your code and its score, as defined by the challenge.
More generally…
…Please make sure to answer the question and provide sufficient detail.
…Avoid asking for help, clarification or responding to other answers (use comments instead).
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5
$begingroup$
I... why did he prove that theorem? Did he just wake up one day and say "I shall solve this!" or did it serve a purpose?
$endgroup$
– Magic Octopus Urn
7 hours ago
$begingroup$
By "any A" do you mean that like using numbers in Python or
long long
s in C++ is invalid?$endgroup$
– HyperNeutrino
6 hours ago
2
$begingroup$
Can we return
0
for input1
? Lynn's answer currently does.$endgroup$
– Erik the Outgolfer
6 hours ago
2
$begingroup$
@SolomonUcko My question is whether we're actually required to output a positive integer or not, though, that quote itself isn't really enough to specify that, and nowhere does it say that the test cases include the least possible output for each input.
$endgroup$
– Erik the Outgolfer
5 hours ago
1
$begingroup$
@SolomonUcko Yes, "positive" excludes 0, but, again, nowhere in the challenge does it say that the output must be positive. Well, technically, it does restrict the output, but you really need to see into the details to figure that out (the challenge text also uses the "N" variable), so it's not at all clear if OP actually intended to restrict the output to the positive integers or if we can output
0
for input1
as well.$endgroup$
– Erik the Outgolfer
5 hours ago