12 lines
222 B
PHP
12 lines
222 B
PHP
<?php
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define('GRID_SIZE',20);
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function factorial($num) {
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if($num == 0)
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return 1;
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else
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return bcmul($num,factorial(bcsub($num,1)));
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}
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echo bcdiv(factorial(2* GRID_SIZE),bcpow(factorial( GRID_SIZE),2));
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