Substring primes: Difference between revisions
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m (→{{header|Phix}}: prefer get_prime()) |
m (→{{header|REXX}}: added a count for the number of primality tests performed.) |
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if verify(x2, 25 , 'M')>0 then iterate /* " X2 part " " " " " */ |
if verify(x2, 25 , 'M')>0 then iterate /* " X2 part " " " " " */ |
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L= length(x) /*obtain the length of the X prime.*/ |
L= length(x) /*obtain the length of the X prime.*/ |
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ptests= ptests + 1 |
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do k=1 for L-1 /*test for primality for all substrings*/ |
do k=1 for L-1 /*test for primality for all substrings*/ |
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do m=k+1 to L; y= substr(x, k, m-1) /*extract a substring from the X prime.*/ |
do m=k+1 to L; y= substr(x, k, m-1) /*extract a substring from the X prime.*/ |
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if $\=='' then say center(1,7)"│" substr($, 2) /*display the list of substring primes.*/ |
if $\=='' then say center(1,7)"│" substr($, 2) /*display the list of substring primes.*/ |
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say; say 'Found ' words($) @sprs |
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say |
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say |
say; say ptests ' primality tests were performed.' |
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exit 0 /*stick a fork in it, we're all done. */ |
exit 0 /*stick a fork in it, we're all done. */ |
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/*──────────────────────────────────────────────────────────────────────────────────────*/ |
/*──────────────────────────────────────────────────────────────────────────────────────*/ |
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genP: !.= 0 |
genP: !.= 0; ptests= 0 /*placeholders for primes (semaphores).*/ |
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@.1=2; @.2=3; @.3=5; @.4=7; @.5=11 /*define some low primes. */ |
@.1=2; @.2=3; @.3=5; @.4=7; @.5=11 /*define some low primes. */ |
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!.2=1; !.3=1; !.5=1; !.7=1; !.11=1 /* " " " " flags. */ |
!.2=1; !.3=1; !.5=1; !.7=1; !.11=1 /* " " " " flags. */ |
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Found 9 primes (base ten) where all substrings are also primes < 500 |
Found 9 primes (base ten) where all substrings are also primes < 500 |
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12 primality tests were performed. |
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</pre> |
</pre> |
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