Clever but doesn't pass n = 70 with node v18.

That was my solution at first.

But got:

expected 3226062132197576 to equal 3226062132197568

on perimeter(70)

Brilliant!

| defaults to the next value if the previous one is falsy, || compares if either comparison is true. 0 | 'String' resolves in String, 1 > 0 || -1 > 3 resolves in true.

niiiice solution!

This is bad in terms of time and performance, because you will have to traverse the array 2 times.

you should update your solution because, it's not valid after some added test cases,

it is called prefix increment

As of January 21, 2025, padStart is experimental. I don't think using it is a good practice. Regarding min/max: a variant with normal conditions (see my solution) would be more readable

Regular expressions

How does this work? Why the gi in the regex? I am just learning regex.

| is technically the bitwise OR operator, while || is the logical OR. The first one works with the binary representation of the values being compared (coerced to numbers), while the second one works directly with the values being compared.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Bitwise_OR

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Logical_OR

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Wow. This is one of the few low-level katas where thinking of how to make a one-liner is not so easy.

brilliant solution

thanks for including formula name I collect these lol