From Angus Croll’s If Hemingway Wrote Javascript: Explained.

Borges’ solution is a variation on the Sieve of Eratosthenes algorithm by which the multiples of each known prime are marked as composite (non-prime). In this case, Borges has long legged monsters take the place of divisors. Each monster straddles one more stair than the monster that went before: 2, 3, 4, 5…up to the square root of the number of the highest stair. (for non-obvious reasons, Borges allows composite-gaited monsters to climb the stairs too). The untrodden stairs are the prime numbers.

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// They speak (I know) of finials, newels and balustrades // of hidden spandrels and eternally clambering, broad-gaited beasts…
// A succession of creatures mount the stairs; // each creature’s stride exceeds that of its predecessor stairs[j] = “stomp”; } } }
// Long-limbed monsters won’t tread on prime numbered stairs. stepsUntrodden.push(i); } }
// Here, then, is our answer. }; |