Find adjacent primes which differ by a square integer: Difference between revisions
Find adjacent primes which differ by a square integer (view source)
Revision as of 11:04, 8 December 2021
, 2 years ago→{{header|jq}}
m (Peak moved page Find adjacents primes which difference is square integer to Find adjacent primes which differ by a square integer: English grammar) |
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Line 361:
240 IF Q = 1 THEN P2 = P: P = T: RETURN
250 GOTO 220</lang>
=={{header|jq}}==
{{works with|jq}}
'''Works with gojq, the Go implementation of jq'''
See [[Erdős-primes#jq]] for a suitable definition of `is_prime` as used here.
'''Preliminaries'''
<lang jq>def lpad($len): tostring | ($len - length) as $l | (" " * $l)[:$l] + .;
# Primes less than . // infinite
def primes:
(. // infinite) as $n
| if $n < 3 then empty
else 2, (range(3; $n) | select(is_prime))
end;</lang>
'''The task'''
<lang jq># Input is given to primes/0 to determine the maximum prime to consider
# Output: [ $prime, $nextPrime, $nextPrime - $prime
def adjacentPrimesWhichDifferBySquare:
def isSquare: sqrt | . == floor;
foreach primes as $p ( {previous: null};
.emit = null
| if .previous != null
and (($p - .previous) | isSquare)
then .emit = [.previous, $p]
else .
end
| .previous = $p;
select(.emit).emit);
# Input is given to primes/0 to determine the maximum prime to consider.
# Gap must be greater than $gap
def task($gap):
def l: lpad(6);
"Adjacent primes under \(.) whose difference is a square > \($gap):",
(adjacentPrimesWhichDifferBySquare
| (.[1] - .[0]) as $diff
| select($diff > 36)
| "\(.[1]|l) - \(.[0]|l) = \($diff|lpad(4))" ) ;
1E6 | task(37)</lang>
{{out}}
As for [[#Algol-68]].
=={{header|Julia}}==
| |||