Untouchable numbers: Difference between revisions
Added Delphi example
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real 11m28.031s
</pre>
=={{header|Delphi}}==
{{libheader| System.SysUtils}}
{{Trans|Go}}
<lang Delphi>
program Untouchable_numbers;
{$APPTYPE CONSOLE}
uses
System.SysUtils;
function SumDivisors(n: Integer): Integer;
begin
Result := 1;
var k := 2;
if not odd(n) then
k := 1;
var i := 1 + k;
while i * i <= n do
begin
if (n mod i) = 0 then
begin
inc(Result, i);
var j := n div i;
if j <> i then
inc(Result, j);
end;
inc(i, k);
end;
end;
function Sieve(n: Integer): TArray<Boolean>;
begin
inc(n);
SetLength(result, n + 1);
for var i := 6 to n do
begin
var sd := SumDivisors(i);
if sd <= n then
result[sd] := True;
end;
end;
function PrimeSieve(limit: Integer): TArray<Boolean>;
begin
inc(limit);
SetLength(result, limit);
Result[0] := True;
Result[1] := True;
var p := 3;
repeat
var p2 := p * p;
if p2 >= limit then
Break;
var i := p2;
while i < limit do
begin
Result[i] := True;
inc(i, 2 * p);
end;
repeat
inc(p, 2);
until not Result[p];
until (False);
end;
function Commatize(n: Double): string;
var
fmt: TFormatSettings;
begin
fmt := TFormatSettings.Create('en-US');
Result := n.ToString(ffNumber, 64, 0, fmt);
end;
begin
var limit := 1000000;
var c := primeSieve(limit);
var s := sieve(63 * limit);
var untouchable: TArray<Integer> := [2, 5];
var n := 6;
while n <= limit do
begin
if not s[n] and c[n - 1] and c[n - 3] then
begin
SetLength(untouchable, Length(untouchable) + 1);
untouchable[High(untouchable)] := n;
end;
inc(n, 2);
end;
writeln('List of untouchable numbers <= 2,000:');
var count := 0;
var i := 0;
while untouchable[i] <= 2000 do
begin
write(commatize(untouchable[i]): 6);
if ((i + 1) mod 10) = 0 then
writeln;
inc(i);
end;
writeln(#10#10, commatize(count): 7, ' untouchable numbers were found <= 2,000');
var p := 10;
count := 0;
for n in untouchable do
begin
inc(count);
if n > p then
begin
var cc := commatize(count - 1);
var cp := commatize(p);
writeln(cc, ' untouchable numbers were found <= ', cp);
p := p * 10;
if p = limit then
Break;
end;
end;
var cu := commatize(Length(untouchable));
var cl := commatize(limit);
writeln(cu:7, ' untouchable numbers were found <= ', cl);
readln;
end.</lang>
=={{header|F_Sharp|F#}}==
===The Function===
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