Concatenate two primes is also prime: Difference between revisions
Concatenate two primes is also prime (view source)
Revision as of 05:53, 13 August 2021
, 2 years ago→{{header|jq}}
Catskill549 (talk | contribs) (added AWK) |
|||
Line 277:
</pre>
=={{header|jq}}==
{{works with|jq}}
'''Works with gojq, the Go implementation of jq'''
'''Preliminaries'''
<lang jq>def is_prime:
. as $n
| if ($n < 2) then false
elif ($n % 2 == 0) then $n == 2
elif ($n % 3 == 0) then $n == 3
elif ($n % 5 == 0) then $n == 5
elif ($n % 7 == 0) then $n == 7
elif ($n % 11 == 0) then $n == 11
elif ($n % 13 == 0) then $n == 13
elif ($n % 17 == 0) then $n == 17
elif ($n % 19 == 0) then $n == 19
else {i:23}
| until( (.i * .i) > $n or ($n % .i == 0); .i += 2)
| .i * .i > $n
end;
# Emit an array of primes less than `.`
def primes:
if . < 2 then []
else
[2] + [range(3; .; 2) | select(is_prime)]
end;
# Pretty-printing
def nwise($n):
def n: if length <= $n then . else .[0:$n] , (.[$n:] | n) end;
n;
def lpad($len): tostring | ($len - length) as $l | (" " * $l)[:$l] + .;
</lang>
'''The task'''
<lang jq># Emit [p1,p2] where p1 < p2 < . and the concatenation is prime
def concatenative_primes:
primes
| range(0;length) as $i
| range($i+1;length) as $j
| [.[$i], .[$j]], [.[$j], .[$i]]
| select( map(tostring) | add | tonumber | is_prime);
[100 | concatenative_primes | join("||")]
| (nwise(10) | map(lpad(6)) | join(" "))</lang>
{{out}}
<pre>
2||3 2||11 2||23 2||29 2||41 2||71 2||83 5||3 3||7 7||3
3||11 11||3 3||13 3||17 17||3 19||3 23||3 29||3 3||31 31||3
3||37 37||3 43||3 3||47 3||53 3||59 59||3 61||3 3||67 67||3
3||73 73||3 3||79 3||83 3||89 3||97 5||23 5||41 5||47 5||71
13||7 7||19 19||7 31||7 7||43 7||61 61||7 67||7 7||73 79||7
7||97 97||7 11||17 11||23 23||11 11||29 41||11 11||53 11||71 83||11
13||19 19||13 13||61 61||13 13||67 13||73 17||23 29||17 17||41 17||47
17||53 17||59 17||83 83||17 17||89 19||31 31||19 37||19 67||19 19||73
19||79 79||19 19||97 97||19 23||41 23||47 47||23 53||23 59||23 23||71
23||83 23||89 89||23 41||29 47||29 29||53 29||71 71||29 83||29 89||29
31||37 61||31 31||67 73||31 43||37 37||61 37||67 67||37 37||79 79||37
37||97 41||53 41||59 89||41 61||43 43||73 43||97 97||43 53||47 47||59
47||83 47||89 59||53 83||53 71||59 67||61 61||73 61||97 67||79 97||67
</pre>
=={{header|Julia}}==
<lang julia>using Primes
Line 291 ⟶ 353:
foreach(p -> print(lpad(last(p), 5), first(p) % 16 == 0 ? "\n" : ""),
catprimes() |> enumerate)
</lang>{{out}}
<pre>
23 37 53 73 113 137 173 193 197 211 223 229 233 241 271 283
293 311 313 317 331 337 347 353 359 367 373 379 383 389 397 433
| |||