【高精类】High_running V0.01

时间：2010-08-22 来源：abcdabcd987

彷徨了两年，终于又回来了cnblogs。因为作为一个喜欢技术的人，把文章放在QQ空间现在容易被扁，又不想破费去买个虚拟主机，想来想去还是cnblogs好，皮也多，人也多，高手更多！加上我关注的除了嵌入式这边没有专门的分类外，其他的分类都很详细，所以以后就定居cnblogs。不知道等到我高中毕业这里会有多少篇随笔。

High_running这个类（名字随便起的，英文不好）主要实现高精度运算，基本任务就是整数加减乘除模，后面再加上浮点数的，再后面优化算法。其实做这个类的主要目的还是熟悉C++，毕竟我总不能拿着这个类去参加NOIP吧？

因为今天时间有限，仓促地编了这么一个开始，只支持+=操作，而且还没处理数组长度问题，还有异常处理等小问题。因为try...catch还没仔细看，所以等看完了再补上去，毕竟主要是为了学习。

高手请无视~！或者给我提提意见更好！

High_running.h

#ifndef _HIGH_RUNNING_H
#define _HIGH_RUNNING_H
#include <iostream>
class High_running
{
public:
    High_running():Data(NULL){}
    High_running(const size_t);
    High_running(const std::string, const size_t);
    High_running& operator+=(const High_running&);
private:
    typedef signed int high;
    int MaxLength;
    int Length;
    high* Data;
    void _init();
    friend std::istream& operator>>(std::istream&, High_running&);
    friend std::ostream& operator<<(std::ostream&, const High_running&);
};
#endif

High_running.cpp

#include <iostream>
#include <string>
#include "High_running.h"

std::istream& operator>>(std::istream& in,High_running& obj)
{
    std::string str;
    in>>str;
    obj.Length=str.size();
    obj._init();
    for (size_t i=0;i!=str.size();++i)
        obj.Data[i]=str[obj.Length-i-1]-48;    
    return in;
}
std::ostream& operator<<(std::ostream& out,const High_running& obj)
{
    for (int i=0;i!=obj.Length;++i)
        out<<(int)obj.Data[obj.Length-i-1];
    return out;
}
void High_running::_init()
{
    if (Data==NULL)
    {
        Data=new high[MaxLength];
        memset(Data,0,sizeof(Data));
    }
}
High_running::High_running(const size_t max)
    :Length(0),MaxLength(max),Data(NULL)
{
    _init();
}
High_running::High_running(const std::string str, const size_t max=0)
    :Length(str.size()),MaxLength(max<=str.size()?str.size():max),Data(NULL)
{
    _init();
    for (size_t i=0;i!=str.size();++i)
        Data[i]=str[Length-i-1]-48;
}
High_running& High_running::operator+=(const High_running& obj)
{
    size_t end = Length < obj.Length ? obj.Length : Length;
    int x = 0;
    for (size_t i=0;i!=end;++i)
    {
        x = Data[i] + obj.Data[i] + x / 10;
        Data[i] = x % 10;
    }
    x /= 10;
    if (x > 0)
    {
        Data[Length]=x;
        ++Length;
    }
    return *this;
}

#include <iostream>
#include "High_running.h"
using namespace std;
int main()
{
    High_running a(256),b(256);
    cin>>a>>b;
    a+=b;
    cout<<a;
    system("pause");
    return 0;
}