Erdős–Woods numbers: Difference between revisions

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=={{header|Python}}==

Original author credit to the Stackexchange website user ovs, who in turn credits user xash.

 

def erdős_woods(n):

COUNT += 1

K += 1

 

=={{header|Wren}}==

{{libheader|Wren-big}}

{{libheader|Wren-fmt}}

{{libheader|Wren-sort}}

It's not easy to find a way of doing this in a reasonable time.

 

I ended up translating the Python 3.8 code (the more readable version) [https://codegolf.stackexchange.com/questions/230509/find-the-erd%C5%91s-woods-origin here], 6th post down, and found the first 20 E-W numbers in around 93 seconds. Much slower than Python which has arbitrary precision numerics built-in nowadays but acceptable for Wren.

import "./fmt" for Conv, Fmt

import "./sort" for Sort

 

var zero = BigInt.zero

var A = BigInt.new(a)

var s = primes.map { |p| Conv.btoi(A % p == 0).toString }.join()[-1..0]

}

}

var partitions = [ [zero, zero, two.pow(np) - one] ]

var cmp = Fn.new { |i, j| (key.call(j) - key.call(i)).sign }

for (i in Sort.merge((1...n).toList, cmp)) {

var newPartitions = []

for (p in partitions) {

var setA = p[0]

}

var N = BigInt.new(n)

result = result ? BigInt.min(result, temp) : temp

}

var k = 3

var count = 0

while (count < 20) {

var a = ew.call(k)

}

k = k + 1

 

{{out}}

<pre>

16 -> 2184

22 -> 3521210

112 -> 1022681262163316216977769066573892020

116 -> 199354011780827861571272685278371171794

</pre>