Strange unique prime triplets: Difference between revisions
Added Delphi example
MaiconSoft (talk | contribs) (Added Delphi example) |
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Found 241580 strange unique prime triplets up to 1000
</pre>
=={{header|Delphi}}==
{{libheader| System.SysUtils}}
{{Trans|Go}}
<lang Delphi>
program Strange_primes;
{$APPTYPE CONSOLE}
uses
System.SysUtils;
function IsPrime(n: Integer): Boolean;
begin
if n < 2 then
exit(false);
if n mod 2 = 0 then
exit(n = 2);
if n mod 3 = 0 then
exit(n = 3);
var d := 5;
while d * d <= n do
begin
if n mod d = 0 then
exit(false);
inc(d, 2);
if n mod d = 0 then
exit(false);
inc(d, 4);
end;
Result := true;
end;
function Commatize(value: Integer): string;
begin
Result := FloatToStrF(value, ffNumber, 10, 0);
end;
function StrangePrimes(n: Integer; countOnly: Boolean): Integer;
begin
var c := 0;
var f := '%2d: %2d + %2d + %2d = %2d'#10;
var s: Integer := 0;
var i := 3;
while i <= n - 4 do
begin
if IsPrime(i) then
begin
var j := i + 2;
while j <= n - 2 do
begin
if IsPrime(j) then
begin
var k := j + 2;
while k <= n do
begin
if IsPrime(k) then
begin
s := i + j + k;
if IsPrime(s) then
begin
inc(c);
if not countOnly then
write(format(f, [c, i, j, k, s]));
end;
end;
inc(k, 2);
end;
end;
inc(j, 2);
end;
end;
inc(i, 2);
end;
Result := c;
end;
begin
Writeln('Unique prime triples under 30 which sum to a prime:');
strangePrimes(29, false);
var cs := commatize(strangePrimes(999, true));
writeln('There are ', cs, ' unique prime triples under 1,000 which sum to a prime.');
readln;
end.</lang>
=={{header|Factor}}==
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