65 lines
1.2 KiB
ObjectPascal
65 lines
1.2 KiB
ObjectPascal
Program Pi_Spigot;
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const
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n = 1000;
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len = 10*n div 3;
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var
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j, k, q, nines, predigit: integer;
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a: array[0..len] of longint;
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function OneLoop(i:integer):integer;
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var
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x: integer;
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begin
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{Only calculate as far as needed }
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{+16 for security digits ~5 decimals}
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i := i*10 div 3+16;
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IF i > len then
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i := len;
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result := 0;
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repeat {Work backwards}
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x := 10*a[i] + result*i;
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result := x div (2*i - 1);
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a[i] := x - result*(2*i - 1);//x mod (2*i - 1)
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dec(i);
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until i<= 0 ;
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end;
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begin
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for j := 1 to len do
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a[j] := 2; {Start with 2s}
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nines := 0;
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predigit := 0; {First predigit is a 0}
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for j := 1 to n do
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begin
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q := OneLoop(n-j);
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a[1] := q mod 10;
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q := q div 10;
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if q = 9 then
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nines := nines + 1
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else
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if q = 10 then
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begin
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write(predigit+1);
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for k := 1 to nines do
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write(0); {zeros}
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predigit := 0;
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nines := 0
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end
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else
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begin
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write(predigit);
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predigit := q;
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if nines <> 0 then
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begin
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for k := 1 to nines do
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write(9);
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nines := 0
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end
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end
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end;
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writeln(predigit);
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end.
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