Earliest difference between prime gaps: Difference between revisions
Earliest difference between prime gaps (view source)
Revision as of 21:07, 2 March 2024
, 3 months agoAdded FreeBASIC
m (→{{header|Wren}}: Minor tidy) |
(Added FreeBASIC) |
||
Line 289:
1000000000 -> distance between start of gap 276=649580171 and start of gap 278=4260928601 is 3611348430
</pre>
=={{header|FreeBASIC}}==
{{trans|C++}}
<syntaxhighlight lang="vbnet">Type PrimeGaps
As Ulong lastPrime
As Ulongint gapStarts(1 To 1e7)
End Type
Function NextPrime(n As Ulong) As Ulong
Dim As Ulong j, i = n + 1
Do
For j = 2 To Sqr(i)
If i Mod j = 0 Then Exit For
Next j
If j > Sqr(i) Then Return i
i += 1
Loop
End Function
Function findGapStart(Byref pg As PrimeGaps, gap As Ulongint) As Ulongint
Dim As Ulongint prev, diff
If pg.gapStarts(gap) <> 0 Then Return pg.gapStarts(gap)
Do
prev = pg.lastPrime
pg.lastPrime = NextPrime(pg.lastPrime)
diff = pg.lastPrime - prev
pg.gapStarts(diff) = prev
If gap = diff Then Return prev
Loop
End Function
Dim Shared As PrimeGaps pg
pg.lastPrime = NextPrime(2)
Dim As Ulongint limit = 1e7
Dim As Integer pm = 10
Dim As Ulongint start1, start2, gap1 = 2, gap2, diff
Do
start1 = findGapStart(pg, gap1)
gap2 = gap1 + 2
start2 = findGapStart(pg, gap2)
diff = Abs(start2 - start1)
If diff > pm Then
Print "Earliest difference >"; pm; " between adjacent prime gap starting primes:"
Print "Gap "; gap1; " starts at "; start1; ", gap "; gap2; " starts at "; start2; ", difference is "; diff; !".\n"
If pm = limit Then Exit Do
pm *= 10
Else
gap1 = gap2
End If
Loop
Sleep</syntaxhighlight>
=={{header|Go}}==
{{trans|Wren}}
| |||