Perfect totient numbers: Difference between revisions
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m (→{{header|REXX}}: optimized the PHI function.) |
m (→{{header|REXX}}: optimized the main DO loop (twice as fast).) |
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@.=. /*memoization array of totient numbers.*/ |
@.=. /*memoization array of totient numbers.*/ |
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$= /*list of the perfect totient numbers. */ |
$= /*list of the perfect totient numbers. */ |
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do j=3 until p==N; |
do j=3 by 2 until p==N; s= phi(j) /*obtain totient number for a number. */ |
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a= s /* [↓] search for a perfect totient #.*/ |
a= s /* [↓] search for a perfect totient #.*/ |
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do until a==1; a= phi(a); s= s + a |
do until a==1; a= phi(a); s= s + a |
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end /*until*/ |
end /*until*/ |
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if s\==j then iterate /*Is J not a perfect totient number? */ |
if s\==j then iterate /*Is J not a perfect totient number? */ |
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p= p + 1 /*bump count of perfect totient numbers*/ |
p= p + 1 /*bump count of perfect totient numbers*/ |
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