Substring primes: Difference between revisions
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Total number of primality tests = 15
</pre>
=={{header|jq}}==
{{works with|jq}}
'''Works with gojq, the Go implementation of jq'''
In the following, we verify that there are only nine "substring primes"
as defined for this task..
See e.g. [[Erd%C5%91s-primes#jq]] for a suitable implementation of `is_prime`.
<lang jq>def emit_until(cond; stream): label $out | stream | if cond then break
$out else . end;
def primes:
2, (range(3;infinite;2) | select(is_prime));
def is_substring(checkPrime):
def isp: if . == "" then true else tonumber|is_prime end;
(if checkPrime then is_prime else true end)
and (tostring
| . as $s
| all(range(0;length) as $i | range($i; length+1) as $j | [$i,$j];
$s[.[0]:.[1]]|isp ));
# Output an array of the substring primes less than or equal to `.`
def substring_primes:
. as $n
| reduce emit_until(. > $n; primes) as $p ( null;
if $p | is_substring(false)
then . += [$p]
else .
end );
# Input: an array of the substring primes less than or equal to 373.
# Output: any other substring primes.
# Comment: if there are any others, they would have to be constructed
# from the numbers in the input array, as by assumption it includes
# all substring primes less than 100.
def verify:
. as $sp
| range(0;length) as $i
| range(0;length) as $j
| ([$sp[$i, $j]] | map(tostring) | add | tonumber) as $candidate
| if $candidate | IN($sp[]) then empty
elif $candidate | is_substring(true) then $candidate
else empty
end;
500 | substring_primes
| "Verifying that the following are the only substring primes:",
.,
"...",
( [verify] as $extra
| if $extra == [] then "done" else $extra end )</lang>
{{out}}
<pre>
Verifying that the following are the only substring primes:
[2,3,5,7,23,37,53,73,373]
...
done
</pre>
=={{header|Julia}}==
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