Skip to main content
Code Golf

Return to Answer

deleted 14 characters in body
Source Link
Neil
Neil
  • 177.2k
  • 12
  • 74
  • 281

Retina, 2929 26 bytes

.+\d+
$*
(?=1+¶=.*?(1+)$)\1|1+$\1
$'
1

Try it online!Try it online! Link includes test cases and header to reformat them to its preferred input (0-indexed k on first line, 1-indexed n on second line). I was inspired by @GB's Ruby answer. Explanation:

.+\d+
$*

Convert to unary.

(?=1+\n=.*?(1+)$)\1|1+$\1
$'

Match every string of n within k, and replace the match with everything after the match. This is k-n, k-2n, k-3n, but n is also after the match, so you get k, k-n, k-2n etc. All that remains is to deleteThis also matches n, which is handled by the alternationsimply deleted (it's no longer needed).

1

Sum the results and convert back to decimal.

Retina, 29 bytes

.+
$*
(?=1+¶(1+)$)\1|1+$
$'
1

Try it online! Link includes test cases and header to reformat them to its preferred input (0-indexed k on first line, 1-indexed n on second line). I was inspired by @GB's Ruby answer. Explanation:

.+
$*

Convert to unary.

(?=1+\n(1+)$)\1|1+$
$'

Match every string of n within k, and replace the match with everything after the match. This is k-n, k-2n, k-3n, but n is also after the match, so you get k, k-n, k-2n etc. All that remains is to delete n, which is handled by the alternation.

1

Sum the results and convert back to decimal.

Retina, 29 26 bytes

\d+
$*
(?=.*?(1+)$)\1
$'
1

Try it online! Link includes test cases and header to reformat them to its preferred input (0-indexed k first, 1-indexed n second). I was inspired by @GB's Ruby answer. Explanation:

\d+
$*

Convert to unary.

(?=.*?(1+)$)\1
$'

Match every string of n within k, and replace the match with everything after the match. This is k-n, k-2n, k-3n, but n is also after the match, so you get k, k-n, k-2n etc. This also matches n, which is simply deleted (it's no longer needed).

1

Sum the results and convert back to decimal.

Source Link
Neil
Neil
  • 177.2k
  • 12
  • 74
  • 281

Retina, 29 bytes

.+
$*
(?=1+¶(1+)$)\1|1+$
$'
1

Try it online! Link includes test cases and header to reformat them to its preferred input (0-indexed k on first line, 1-indexed n on second line). I was inspired by @GB's Ruby answer. Explanation:

.+
$*

Convert to unary.

(?=1+\n(1+)$)\1|1+$
$'

Match every string of n within k, and replace the match with everything after the match. This is k-n, k-2n, k-3n, but n is also after the match, so you get k, k-n, k-2n etc. All that remains is to delete n, which is handled by the alternation.

1

Sum the results and convert back to decimal.