43 lines
965 B
Text
43 lines
965 B
Text
func IsPrime(N); \Return 'true' if N is prime
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int N, I;
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[if N <= 2 then return N = 2;
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if (N&1) = 0 then \even >2\ return false;
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for I:= 3 to sqrt(N) do
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[if rem(N/I) = 0 then return false;
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I:= I+1;
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];
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return true;
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];
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int PT(1_000_000);
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func G(E); \Ways E can be expressed as sum of two primes
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int E, C, I, J, T;
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[C:= 0; I:= 0;
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loop [J:= I;
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if PT(J) + PT(I) > E then return C;
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loop [T:= PT(J) + PT(I);
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if T = E then C:= C+1;
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if T > E then quit;
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J:= J+1;
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];
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I:= I+1;
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];
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];
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int I, N;
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[I:= 0; \make prime table
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for N:= 2 to 1_000_000 do
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if IsPrime(N) then
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[PT(I):= N; I:= I+1];
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I:= 4; \show first 100 G numbers
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Format(4, 0);
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for N:= 1 to 100 do
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[RlOut(0, float(G(I)));
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if rem(N/10) = 0 then CrLf(0);
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I:= I+2;
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];
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CrLf(0);
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Text(0, "G(1,000,000) = "); IntOut(0, G(1_000_000));
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CrLf(0);
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]
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