Heim > Backend-Entwicklung > PHP-Tutorial > 【分享】PHP int 超大溢出整数的 加减运算函数,如果有更好的方法欢迎探讨

【分享】PHP int 超大溢出整数的 加减运算函数,如果有更好的方法欢迎探讨

WBOY
Freigeben: 2016-06-23 14:20:11
Original
972 Leute haben es durchsucht

PHP 溢出 加减运算 超大整数

分享一个溢出整数加减的运算函数,刚刚写的,对于溢出的整数可以用这个来进行加减运算。
遗憾的几点是:
一代码太多;二只有加减运算,乘除取余都没有;
Nach dem Login kopieren



其实还有一个更简便的方式就是用SQL数据库的:SELECT n1+n2;
mysql> SELECT 11234123413241341234123412341234+1;+------------------------------------+| 11234123413241341234123412341234+1 |+------------------------------------+|   11234123413241341234123412341235 |+------------------------------------+1 row in set (0.00 sec)mysql> SELECT 11234123413241341234123412341234*12341234123;+----------------------------------------------+| 11234123413241341234123412341234*12341234123 |+----------------------------------------------+|   138642947209487270472850788378836360727782 |+----------------------------------------------+1 row in set (0.00 sec)
Nach dem Login kopieren


如果有更好的方法,请随时回帖或者发个信息给我。欢迎探讨。

/* big int operate [by fuzb 20130826] */function bigintO($num1,$op,$num2){    $arr = array();    $endop = '';    $num1o = $num1;    $num2o = $num2;    if($num1 < 0)    {        $c1 = -1;        $num1 = preg_replace('/^(-)/','',$num1);    } else {        $c1 = 1;    }    if($num2 < 0)    {        $c2 = -1;        $num2 = preg_replace('/^(-)/','',$num2);    } else {        $c2 = 1;    }    $len1 = strlen($num1);    $len2 = strlen($num2);    $len = max(strlen($num1),strlen($num2));    if($len1 < $len) $num1 = str_pad('0',$len - $len1).$num1;    if($len2 < $len) $num2 = str_pad('0',$len - $len2).$num2;    if($op == '+')    {        if($c1 == $c2)        {            $endop = $c1 > 0 ? '':'-';        } else {            $endop = abs($num1o) > abs($num2o) ? $c1:$c2;            $endop = $endop > 0 ? '':'-';        }        $cc = $endop == '-' ? -1:1;        for($i=0; $i< $len; $i++)        {            $n1 = intval($num1{$i});            $n2 = intval($num2{$i});            $n = $n1*$c1+$n2*$c2;            $arr[$i] = $n*$cc;        }    } else if($op == '-') {        if($c1 < 0)        {            $endop = $c2 > 0 ? '-':(abs($num1o) > abs($num2o) ? '-':'');        } else {            $endop = $c2 > 0 ? (abs($num1o) > abs($num2o) ? '':'-'):'';        }        $cc = $endop == '-' ? -1:1;        for($i=0;$i < $len;$i++)        {            $n1 = intval($num1{$i});            $n2 = intval($num2{$i});            $n = $n1*$c1-$n2*$c2;            $arr[$i] = $n*$cc;        }    }    $len = count($arr);    $arr2 = array();    for($i=0;$i< $len;$i++)    {        if($arr[$i] < 0) {            $n = $arr[$i] + 10;            $arr2[$i] = $n;            $j = $i-1;            while(true)            {                if($arr2[$j] == 0)                {                    $arr2[$j] = 9;                    $j--;                } else {                    $arr2[$j]--;                    break;                }            }        } else if($arr[$i] > 9) {            $n = $arr[$i] - 10;            $arr2[$i] = $n;            $j = $i-1;            while(true)            {                if($arr2[$j] == 9)                {                    $arr2[$j] = 0;                    $j--;                } else {                    $arr2[$j]++;                    break;                }            }        } else {            $arr2[$i] = $arr[$i];        }    }    $value = $endop.preg_replace('/^(0{1,})/','',implode($arr2));    return strlen($value) > 0 ? $value : '0';}
Nach dem Login kopieren




测试:
$a = '-12345678901234567890123456789';$b = '1';$c = bigintO($a,'+',$b);var_dump($a); var_dump($b); var_dump($c);exit();/*输出:string '-12345678901234567890123456789' (length=30)string '1' (length=1)string '-12345678901234567890123456788' (length=30)*/
Nach dem Login kopieren


回复讨论(解决方案)

php 已经提供了 BC 和 GMP 两个高精度数学运算函数库

bcadd ? Add two arbitrary precision numbersbccomp ? Compare two arbitrary precision numbersbcdiv ? Divide two arbitrary precision numbersbcmod ? Get modulus of an arbitrary precision numberbcmul ? Multiply two arbitrary precision numberbcpow ? Raise an arbitrary precision number to anotherbcpowmod ? Raise an arbitrary precision number to another, reduced by a specified modulusbcscale ? Set default scale parameter for all bc math functionsbcsqrt ? Get the square root of an arbitrary precision numberbcsub ? Subtract one arbitrary precision number from another
Nach dem Login kopieren
gmp_abs ? Absolute valuegmp_add ? Add numbersgmp_and ? Bitwise ANDgmp_clrbit ? Clear bitgmp_cmp ? Compare numbersgmp_com ? Calculates one's complementgmp_div_q ? Divide numbersgmp_div_qr ? Divide numbers and get quotient and remaindergmp_div_r ? Remainder of the division of numbersgmp_div ? 别名 gmp_div_qgmp_divexact ? Exact division of numbersgmp_fact ? Factorialgmp_gcd ? Calculate GCDgmp_gcdext ? Calculate GCD and multipliersgmp_hamdist ? Hamming distancegmp_init ? Create GMP numbergmp_intval ? Convert GMP number to integergmp_invert ? Inverse by modulogmp_jacobi ? Jacobi symbolgmp_legendre ? Legendre symbolgmp_mod ? Modulo operationgmp_mul ? Multiply numbersgmp_neg ? Negate numbergmp_nextprime ? Find next prime numbergmp_or ? Bitwise ORgmp_perfect_square ? Perfect square checkgmp_popcount ? Population countgmp_pow ? Raise number into powergmp_powm ? Raise number into power with modulogmp_prob_prime ? Check if number is "probably prime"gmp_random ? Random numbergmp_scan0 ? Scan for 0gmp_scan1 ? Scan for 1gmp_setbit ? Set bitgmp_sign ? Sign of numbergmp_sqrt ? Calculate square rootgmp_sqrtrem ? Square root with remaindergmp_strval ? Convert GMP number to stringgmp_sub ? Subtract numbersgmp_testbit ? Tests if a bit is setgmp_xor ? Bitwise XOR
Nach dem Login kopieren
Quelle:php.cn
Erklärung dieser Website
Der Inhalt dieses Artikels wird freiwillig von Internetnutzern beigesteuert und das Urheberrecht liegt beim ursprünglichen Autor. Diese Website übernimmt keine entsprechende rechtliche Verantwortung. Wenn Sie Inhalte finden, bei denen der Verdacht eines Plagiats oder einer Rechtsverletzung besteht, wenden Sie sich bitte an admin@php.cn
Beliebte Tutorials
Mehr>
Neueste Downloads
Mehr>
Web-Effekte
Quellcode der Website
Website-Materialien
Frontend-Vorlage