34 lines
534 B
Rexx
34 lines
534 B
Rexx
-- 21 Feb 2026
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include Setting
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say 'LEGENDRE PRIME COUNTER (NO MEMOIZATION)'
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say version
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say
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numeric digits 10
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do n = 0 to 9
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call Time('r')
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a = 10**n; p = Pie(a)
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say '10^'n Right(p,9) Format(Time('e'),3,3)'s'
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end
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exit
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Pie:
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procedure expose Prim. Memo.
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arg xx
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if xx < 3 then
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return 0+(xx=2)
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n = Primes(Isqrt(xx))
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return Phi(xx,n)+n-1
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Phi:
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procedure expose Prim.
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arg xx,yy
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if yy < 2 then
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return xx-(xx%2)*(yy=1)
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p = Prim.yy
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if xx <= p then
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return 1
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return Phi(xx,yy-1)-Phi(xx%p,yy-1)
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-- Primes; Isqrt
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include Math
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