54 lines
931 B
ObjectPascal
54 lines
931 B
ObjectPascal
program Perfect_totient_numbers;
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{$APPTYPE CONSOLE}
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uses
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System.SysUtils;
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function totient(n: Integer): Integer;
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begin
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var tot := n;
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var i := 2;
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while i * i <= n do
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begin
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if (n mod i) = 0 then
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begin
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while (n mod i) = 0 do
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n := n div i;
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dec(tot, tot div i);
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end;
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if i = 2 then
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i := 1;
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inc(i, 2);
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end;
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if n > 1 then
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dec(tot, tot div n);
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Result := tot;
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end;
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begin
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var perfect: TArray<Integer>;
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var n := 1;
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while length(perfect) < 20 do
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begin
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var tot := n;
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var sum := 0;
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while tot <> 1 do
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begin
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tot := totient(tot);
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inc(sum, tot);
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end;
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if sum = n then
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begin
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SetLength(perfect, Length(perfect) + 1);
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perfect[High(perfect)] := n;
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end;
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inc(n, 2);
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end;
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writeln('The first 20 perfect totient numbers are:');
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write('[');
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for var e in perfect do
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write(e, ' ');
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writeln(']');
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readln;
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end.
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