15 lines
281 B
PHP
15 lines
281 B
PHP
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<?php
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function fib($n) {
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if ($n < 0)
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throw new Exception('Negative numbers not allowed');
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$f = function($n) use (&$f) {
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if ($n < 2)
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return 1;
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else
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return $f($n-1) + $f($n-2);
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};
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return $f($n);
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}
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echo fib(8), "\n";
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?>
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