35 lines
986 B
Plaintext
35 lines
986 B
Plaintext
procedure main()
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limit := 2^19
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write("Perfect numbers up to ",limit," (using rational arithmetic):")
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every write(is_perfect(c := 2 to limit))
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write("End of perfect numbers")
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# verify the rest of the implementation
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zero := makerat(0) # from integer
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half := makerat(0.5) # from real
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qtr := makerat("1/4") # from strings ...
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one := makerat("1")
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mone := makerat("-1")
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verifyrat("eqrat",zero,zero)
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verifyrat("ltrat",zero,half)
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verifyrat("ltrat",half,zero)
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verifyrat("gtrat",zero,half)
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verifyrat("gtrat",half,zero)
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verifyrat("nerat",zero,half)
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verifyrat("nerat",zero,zero)
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verifyrat("absrat",mone,)
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end
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procedure is_perfect(c) #: test for perfect numbers using rational arithmetic
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rsum := rational(1, c, 1)
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every f := 2 to sqrt(c) do
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if 0 = c % f then
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rsum := addrat(rsum,addrat(rational(1,f,1),rational(1,integer(c/f),1)))
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if rsum.numer = rsum.denom = 1 then
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return c
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end
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