26 lines
718 B
Plaintext
26 lines
718 B
Plaintext
$table = (
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(0, 3, 1, 7, 5, 9, 8, 6, 4, 2),
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(7, 0, 9, 2, 1, 5, 4, 8, 6, 3),
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(4, 2, 0, 6, 8, 7, 1, 3, 5, 9),
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(1, 7, 5, 0, 9, 8, 3, 4, 2, 6),
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(6, 1, 2, 3, 0, 4, 5, 9, 7, 8),
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(3, 6, 7, 4, 2, 0, 9, 5, 8, 1),
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(5, 8, 6, 9, 7, 2, 0, 1, 3, 4),
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(8, 9, 4, 5, 3, 6, 2, 0, 1, 7),
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(9, 4, 3, 8, 6, 1, 7, 2, 0, 5),
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(2, 5, 8, 1, 4, 3, 6, 7, 9, 0)
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)
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function Test-Damm([string]$s) {
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$interim = 0
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foreach ($c in $s.ToCharArray()) {
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$interim = $table[$interim][[int]$c - [int][char]'0']
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}
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return $interim -eq 0
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}
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foreach ($number in 5724, 5727, 112946, 112949) {
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$validity = if (Test-Damm $number) {'valid'} else {'invalid'}
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'{0,6} is {1}' -f $number, $validity
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}
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