Ormiston triples: Difference between revisions
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Line 871:
return n
.
func digs n .
while n > 0
n = n div 10
r += pow 10 d▼
.
return r
Line 916 ⟶ 914:
<1 billion: 368
</pre>
=={{header|FreeBASIC}}==
{{trans|XPLo}}
<syntaxhighlight lang="vbnet">Function GetSig(Byval N As Uinteger) As Uinteger 'Return signature of N
'A "signature" is the count of each digit in N packed into a 32-bit word
Dim As Uinteger Sig = 0
Do While N > 0
Sig += 1 Shl (N Mod 10)
Loop
Return Sig
End Function
Dim As Uinteger limite = 1e9
Dim Shared As Boolean Sieve(limite)
Sub MakeSieve(Size As Uinteger) 'Make prime number sieve
Dim As Uinteger Prime, i, K
Size \= 2 'ignore even numbers
For i = 0 To Size 'set Sieve flags all true
Sieve(i) = True
Next
For i = 0 To Size
If Sieve(i) Then 'found a prime, which is equal to
Prime = i * 2 + 3 ' twice the index + 3
K = i + Prime 'first multiple to strike off
While K <= Size 'strike off all multiples
Sieve(K) = False
K += Prime
Wend
End If
Next
End Sub
MakeSieve(limite)
Print "Smallest members of first 25 Ormiston triples:"
Dim As Uinteger Cnt = 0, N0 = 0, N1 = 0, Sig0 = 0, Sig1 = 0, N = 3, Sig
Dim As Double t0 = Timer
Do
If Sieve(N \ 2 - 1) Then ' is prime
Sig = GetSig(N)
If Sig = Sig0 Andalso Sig = Sig1 Then
Cnt += 1
If Cnt <= 25 Then
Print Using "#,###,###,###"; N0;
If Cnt Mod 5 = 0 Then Print
End If
End If
Sig0 = Sig1: Sig1 = Sig
N0 = N1: N1 = N
End If
If N >= limite Then Print Cnt; " Ormiston triples before one billion." : Exit Do
N += 2
Loop
Sleep</syntaxhighlight>
=={{header|Go}}==
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