71 lines
1.5 KiB
ObjectPascal
71 lines
1.5 KiB
ObjectPascal
function IsPrime(N: int64): boolean;
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{Fast, optimised prime test}
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var I,Stop: int64;
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begin
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if (N = 2) or (N=3) then Result:=true
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else if (n <= 1) or ((n mod 2) = 0) or ((n mod 3) = 0) then Result:= false
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else
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begin
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I:=5;
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Stop:=Trunc(sqrt(N+0.0));
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Result:=False;
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while I<=Stop do
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begin
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if ((N mod I) = 0) or ((N mod (I + 2)) = 0) then exit;
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Inc(I,6);
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end;
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Result:=True;
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end;
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end;
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function IsMagnanimous(N: Integer): boolean;
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var S,S1,S2: string;
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var I,I1,I2: integer;
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begin
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Result:=True;
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if N<10 then exit;
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Result:=False;
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S:=IntToStr(N);
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for I:=2 to Length(S) do
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begin
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S1:=Copy(S,1,I-1);
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S2:=Copy(S,I,(Length(S)-I)+1);
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I1:=StrToInt(S1);
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I2:=StrToInt(S2);
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if not IsPrime(I1+I2) then exit;
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end;
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Result:=True;
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end;
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procedure MagnanimousRange(Memo: TMemo; Start,Stop: integer);
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var I,MagCnt,ItemCnt: integer;
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var S: string;
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begin
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S:='';
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MagCnt:=0;
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ItemCnt:=0;
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for I:=0 to High(Integer) do
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if IsMagnanimous(I) then
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begin
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Inc(MagCnt);
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if MagCnt>=Start then
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begin
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if MagCnt>Stop then break;
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S:=S+Format('%12d',[I]);
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Inc(ItemCnt);
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if (ItemCnt mod 5)=0 then S:=S+#$0D#$0A;
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end;
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end;
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Memo.Lines.Add(S);
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end;
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procedure MagnanimousNumbers(Memo: TMemo);
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begin
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Memo.Lines.Add('First 45 Magnanimous Numbers');
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MagnanimousRange(Memo,0,45);
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Memo.Lines.Add('Magnanimous Numbers 241 through 250');
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MagnanimousRange(Memo,241,250);
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Memo.Lines.Add('Magnanimous Numbers 391 through 400');
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MagnanimousRange(Memo,391,400);
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end;
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