C ++中的大数字库
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/12988099/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Big numbers library in c++
提问by Rontogiannis Aristofanis
I'm doing a project which requires really big numbers, up to 100 digits. I have read that java supports big integers (java.Math.BigInteger), and I want to know if there is something like that in C++. So, here is my question: Is there a standard or non-standard c++ library which implements big integers?
我正在做一个需要非常大的数字的项目，最多 100 位数字。我读过java支持大整数（java.Math.BigInteger），我想知道C++中是否有类似的东西。所以，这是我的问题：是否有实现大整数的标准或非标准 C++ 库？
Note:If there is no standard implementation for big integers, I would like a simplenon-standard. Thanks in advance.
注意：如果没有大整数的标准实现，我想要一个简单的非标准。提前致谢。
回答by saeedn
The GNU Multiple Precision Arithmetic Library does what you want http://gmplib.org/
GNU 多精度算术库可以满足您的需求http://gmplib.org/
Gnu MP is a C library but it has a C++ class Interfaceand if you are interested only in big integers, you may just deal with mpz_class. Look at the sample below which I took from the page C++ Interface General
Gnu MP 是一个 C 库，但它有一个C++ 类接口，如果你只对大整数感兴趣，你可以只处理mpz_class. 看看下面我从页面C++ Interface General 中获取的示例
int main (void)
{
mpz_class a, b, c;
a = 1234;
b = "-5678";
c = a+b;
cout << "sum is " << c << "\n";
cout << "absolute value is " << abs(c) << "\n";
return 0;
}
回答by user2001885
Unfortunately, there is no standard library for big numbers. You said you are looking for a "simple" library, the simplest library I know of is InfInt. It consists of just one header file. Its usage is fairly simple. Here is a sample code:
不幸的是，没有大数字的标准库。您说您正在寻找一个“简单”的库，我所知道的最简单的库是InfInt。它只包含一个头文件。它的用法相当简单。这是一个示例代码：
InfInt myint1 = "15432154865413186646848435184100510168404641560358";
InfInt myint2 = 156341300544608LL;
myint1 *= --myint2 - 3;
std::cout << myint1 << std::endl;
回答by john
You said you want a simple interface/implementation, here's one http://www.di-mgt.com.au/bigdigits.html. Personally I'd still go for GMP however.
你说你想要一个简单的界面/实现，这是一个http://www.di-mgt.com.au/bigdigits.html。就个人而言，我仍然会选择 GMP。
回答by my time
You will be taking input in a char array, and then will change it into an int array. The size of array can also be changed.
您将在 char 数组中输入，然后将其更改为 int 数组。数组的大小也可以改变。
#include<iostream>
using std::cout;
using std::cin;
using std::endl;
int main()
{
int b, i, arrayint[100];
char arraychar[100];
for(i = 0; i < 100; i++)
cin >> arraychar[i];
for(i = 0; i < 100; i++)
cout << arraychar[i];
cout << endl;
for(i = 0; i < 100; i++)
arrayint[i] = arraychar[i] - '0';
for(i = 0; i < 100; i++)
cout << arrayint[i];
return 0;
}
