Substring primes: Difference between revisions

</pre>

=={{header|Wren}}==

{{libheader|Wren-math}}

<lang ecmascript>import "/math" for Int

var getDigits = Fn.new { |n|

var digits = []

while (n > 0) {

digits.add(n%10)

n = (n/10).floor

}

return digits[-1..0]

}

var primes = Int.primeSieve(499)

var sprimes = []

for (p in primes) {

var digits = getDigits.call(p)

var b1 = digits.all { |d| Int.isPrime(d) }

if (b1) {

if (digits.count < 3) {

sprimes.add(p)

} else {

var b2 = Int.isPrime(digits[0] * 10 + digits[1])

var b3 = Int.isPrime(digits[1] * 10 + digits[2])

if (b2 && b3) sprimes.add(p)

}

}

}

System.print("Found %(sprimes.count) primes < 500 where all substrings are also primes, namely:")

System.print(sprimes)</lang>

{{out}}

<pre>

Found 9 primes < 500 where all substrings are also primes, namely:

[2, 3, 5, 7, 23, 37, 53, 73, 373]