Consecutive primes with ascending or descending differences: Difference between revisions
Consecutive primes with ascending or descending differences (view source)
Revision as of 19:35, 20 November 2023
, 6 months agoAdded Easylang
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</pre>
=={{header|EasyLang}}==
<syntaxhighlight>
fastfunc nextprim num .
repeat
i = 2
while i <= sqrt num and num mod i <> 0
i += 1
.
until num mod i <> 0
num += 1
.
return num
.
proc getseq dir . maxprim maxcnt .
maxcnt = 0
pri = 2
repeat
prev = pri
pri = nextprim (pri + 1)
until pri > 1000000
d0 = d
d = (pri - prev) * dir
if d > d0
cnt += 1
else
if cnt > maxcnt
maxcnt = cnt
maxprim = prim0
.
prim0 = prev
cnt = 1
.
.
.
proc outseq pri max . .
write pri & " "
for i to max
pri = nextprim (pri + 1)
write pri & " "
.
print ""
.
getseq 1 pri max
outseq pri max
getseq -1 pri max
outseq pri max
</syntaxhighlight>
=={{header|F_Sharp|F#}}==
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Real: 00:00:04.708
</pre>
=={{header|Factor}}==
{{works with|Factor|0.99 2021-02-05}}
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;{.(\: #@>) tris <@~.@,;._1~ >:/ 2 -/\ |: tris=: 3 ]\ p: i. p:inv 1e6
322171 322193 322213 322229 322237 322243 322247 322249</syntaxhighlight>
=={{header|Java}}==
<syntaxhighlight lang="java">
import java.util.ArrayList;
import java.util.BitSet;
import java.util.List;
public final class ConsecutivePrimes {
public static void main(String[] aArgs) {
final int limit = 1_000_000;
List<Integer> primes = listPrimeNumbers(limit);
List<Integer> asc = new ArrayList<Integer>();
List<Integer> desc = new ArrayList<Integer>();
List<List<Integer>> maxAsc = new ArrayList<List<Integer>>();
List<List<Integer>> maxDesc = new ArrayList<List<Integer>>();
int maxAscSize = 0;
int maxDescSize = 0;
for ( int prime : primes ) {
final int ascSize = asc.size();
if ( ascSize > 1 && prime - asc.get(ascSize - 1) <= asc.get(ascSize - 1) - asc.get(ascSize - 2) ) {
asc = new ArrayList<Integer>(asc.subList(ascSize - 1, asc.size()));
}
asc.add(prime);
if ( asc.size() >= maxAscSize ) {
if ( asc.size() > maxAscSize ) {
maxAscSize = asc.size();
maxAsc.clear();
}
maxAsc.add( new ArrayList<Integer>(asc) );
}
final int descSize = desc.size();
if ( descSize > 1 && prime - desc.get(descSize - 1) >= desc.get(descSize - 1) - desc.get(descSize - 2) ) {
desc = new ArrayList<Integer>(desc.subList(descSize - 1, desc.size()));
}
desc.add(prime);
if ( desc.size() >= maxDescSize ) {
if ( desc.size() > maxDescSize ) {
maxDescSize = desc.size();
maxDesc.clear();
}
maxDesc.add( new ArrayList<Integer>(desc) );
}
}
System.out.println("Longest run(s) of ascending prime gaps up to " + limit + ":");
for ( List<Integer> list : maxAsc ) {
displayResult(list);
}
System.out.println();
System.out.println("Longest run(s) of descending prime gaps up to " + limit + ":");
for( List<Integer> list : maxDesc ) {
displayResult(list);
}
}
private static List<Integer> listPrimeNumbers(int aLimit) {
BitSet sieve = new BitSet(aLimit + 1);
sieve.set(2, aLimit + 1);
for ( int i = 2; i <= Math.sqrt(aLimit); i = sieve.nextSetBit(i + 1) ) {
for ( int j = i * i; j <= aLimit; j = j + i ) {
sieve.clear(j);
}
}
List<Integer> result = new ArrayList<Integer>(sieve.cardinality());
for ( int i = 2; i >= 0; i = sieve.nextSetBit(i + 1) ) {
result.add(i);
}
return result;
}
private static void displayResult(List<Integer> aList) {
for ( int i = 0; i < aList.size(); i++ ) {
if ( i > 0 ) {
System.out.print(" (" + ( aList.get(i) - aList.get(i - 1) ) + ") ");
}
System.out.print(aList.get(i));
}
System.out.println();
}
}
</syntaxhighlight>
{{ out }}
<pre>
Longest run(s) of ascending prime gaps up to 1000000:
128981 (2) 128983 (4) 128987 (6) 128993 (8) 129001 (10) 129011 (12) 129023 (14) 129037
402581 (2) 402583 (4) 402587 (6) 402593 (8) 402601 (12) 402613 (18) 402631 (60) 402691
665111 (2) 665113 (4) 665117 (6) 665123 (8) 665131 (10) 665141 (12) 665153 (24) 665177
Longest run(s) of descending prime gaps up to 1000000:
322171 (22) 322193 (20) 322213 (16) 322229 (8) 322237 (6) 322243 (4) 322247 (2) 322249
752207 (44) 752251 (12) 752263 (10) 752273 (8) 752281 (6) 752287 (4) 752291 (2) 752293
</pre>
=={{header|jq}}==
Line 1,452 ⟶ 1,604:
=={{header|Wren}}==
{{libheader|Wren-math}}
<syntaxhighlight lang="
var LIMIT = 999999
| |||