Twin primes: Difference between revisions
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(→{{header|ALGOL 68}}: Obvious optimisation and remove unnecessary comments) |
(→{{header|ALGOL 68}}: Revised task requirements - check for primes less than the specified number) |
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# note 2 cannot be one of the primes in a twin prime pair, so we start at 3 # |
# note 2 cannot be one of the primes in a twin prime pair, so we start at 3 # |
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INT twin count := 0; |
INT twin count := 0; |
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FOR p FROM 3 BY 2 TO max number DO IF primes[ p ] AND primes[ p - 2 ] THEN twin count +:= 1 FI OD; |
FOR p FROM 3 BY 2 TO max number - 1 DO IF primes[ p ] AND primes[ p - 2 ] THEN twin count +:= 1 FI OD; |
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print( ( "twin prime pairs below ", whole( max number, 0 ), ": ", whole( twin count, 0 ), newline ) ) |
print( ( "twin prime pairs below ", whole( max number, 0 ), ": ", whole( twin count, 0 ), newline ) ) |
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END</lang> |
END</lang> |
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