BCMath 任意精度数学

简介
安装／配置
预定义常量
BC 数学函数
- bcadd — Add two arbitrary precision numbers
- bccomp — Compare two arbitrary precision numbers
- bcdiv — Divide two arbitrary precision numbers
- bcmod — Get modulus of an arbitrary precision number
- bcmul — Multiply two arbitrary precision number
- bcpow — Raise an arbitrary precision number to another
- bcpowmod — Raise an arbitrary precision number to another, reduced by a specified modulus
- bcscale — Set default scale parameter for all bc math functions
- bcsqrt — Get the square root of an arbitrary precision number
- bcsub — Subtract one arbitrary precision number from another

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ClaudiuS ¶

2 months ago


Needed to compute some permutations and found the BC extension great but poor on functions, so untill this gets implemented here's the factorial function:



<?php

/* BC FACTORIAL

 * n! = n * (n-1) * (n-2) .. 1 [eg. 5! = 5 * 4 * 3 * 2 * 1 = 120]

 */

function bcfact($n){

    $factorial=$n;

    while (--$n>1) $factorial=bcmul($factorial,$n);

    return $factorial;

}



print bcfact(50); 

//30414093201713378043612608166064768844377641568960512000000000000

?>

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