只完成了输入和输出部分，一起来做啊……

我写得了,用vector来写不多好吗?

偶也在用C#写huge int。现在完成了加减法和大小比较。目前要解决的是乘除问题。

我乘已经完成了，现在在写除

我用动态数组, 不用维护size.

什么动态数组？

已经完成了~~除法效率很慢，用的方法是循环减法，听人介绍的方法，没想到效率这么慢

以下是清单：
（今天只到这里）

#include<iostream.h>
class hugeint
{
public:
    hugeint(int);
    hugeint(long);
    hugeint(hugeint&);
    ~hugeint();
    inline long getsize(){return size;};
    inline int elem(long index){return data[index];};
    hugeint& operator = (char*);
    hugeint& operator = (hugeint&);    
protected:
    void inverse();
    void clear();
    int inc();
    int *data;
    long size;
//friends:
    friend ostream& operator << (ostream&,hugeint&);
    friend hugeint operator + (hugeint&,hugeint&);
    friend hugeint operator - (hugeint&,hugeint&);
    friend hugeint operator * (hugeint&,hugeint&);
    friend hugeint operator / (hugeint&,hugeint&);
    friend hugeint operator % (hugeint&,hugeint&);
    friend int add(hugeint&,hugeint&,int,int bitm=0);
    friend int mul(hugeint&,int);
    friend int div(hugeint&,hugeint&,hugeint&,hugeint&);
};



#include<string.h>
#include<iomanip.h>
#include "hugeint.h"
#define ERRORMSG "Over Flow!"
//public:
hugeint::hugeint(int n)
{
    size=(long)n/4;
    data=new int[size];
    for(long i=0;i<size;++i)data[i]=0;
}
hugeint::hugeint(long n)
{
    size=n/4;
    data=new int[size];
    for(long i=0;i<size;++i)data[i]=0;
}
hugeint::hugeint(hugeint& a)
{
    size=a.getsize();
    data=new int[size];
    for(long i=0;i<size;++i)data[i]=a.elem(i);
}
hugeint::~hugeint()
{
    delete[]data;
}
//protected:

void hugeint::inverse()
{
    for(long i=0;i<size;++i)data[i]=9999-data[i];
}
void hugeint::clear()
{
    for(long i=0;i<size;++i)data[i]=0;
}
int hugeint::inc()
{
    int s=1;
    for(long i=0;s&&i<size;++i)
    {
        int t=data[i]+s;
        data[i]=t%10000;
        s=t/10000;
    }
    if(s)return -1;
    return 0;
}
//friends:
ostream& operator <<(ostream& out,hugeint& a)
{
    int *p=a.data+a.size-1;
    while(!*p)--p;
    out<<*p--;
    while(p>(a.data-1))
        out<<setw(4)<<setfill('0')<<*p--;
    return out;
}
hugeint& hugeint::operator = (char *str)
{
    long len=strlen(str),count=0;
    if(len>(size<<2))return *this;
    char *p=str+len-1;
    int t,i;
    while(1)
    {
        if((p-str)<4)break;
        t=0;
        char *ph=p-3;
        for(int i=0;i<4;++i)
        {
            t*=10;
            t+=ph[i]-'0';
        }
        data[count++]=t;
        p-=4;
    }
    t=0;
    for(i=0;i<=p-str;++i)
    {
        t*=10;
        t+=str[i]-'0';
    }
    data[count]=t;
    return *this;
}
hugeint& hugeint::operator = (hugeint& a)
{
    if(size!=a.getsize())return *this;
    for(long i=0;i<size;++i)data[i]=a.elem(i);
    return *this;
}
hugeint operator +(hugeint& a,hugeint& b)
{
    hugeint temp=a;
    if(add(temp,b,0))
        cerr<<ERRORMSG<<endl;
    return temp;
}
hugeint operator -(hugeint& a,hugeint& b)
{
    hugeint temp1=a,temp2=b;
    temp2.inverse();
    add(temp1,temp2,1);
    return temp1;
}
hugeint operator *(hugeint& a,hugeint& b)
{
    hugeint temp1=a,temp2=temp1;
    temp1.clear();
    for(long i=0;i<b.size;++i)
    {
        temp2=a;
        mul(temp2,b.data[i]);
        add(temp1,temp2,0,i);
    }
    return temp1;
}
hugeint operator /(hugeint& a,hugeint& b)
{
    hugeint stemp=a,rtemp=a;
    if(div(a,b,stemp,rtemp))
        cerr<<ERRORMSG<<endl;
    return stemp;
}
hugeint operator %(hugeint& a,hugeint& b)
{
    hugeint stemp=a,rtemp=a;
    if(div(a,b,stemp,rtemp))
        cerr<<ERRORMSG<<endl;
    return rtemp;
}
int add(hugeint& a,hugeint& b,int s,int bitm)
{
    long size;
    if((size=a.size)!=b.size)return -2;
    for(long i=bitm;i<size;++i)
    {
        int t=a.data[i]+b.data[i-bitm]+s;
        a.data[i]=t%10000;
        s=t/10000;
    }
    if(s)return -1;
    return 0;
}
int mul(hugeint& a,int n)
{
    int s=0;
    for(long i=0;i<a.size;++i)
    {
        long t=a.data[i]*n+s;
        a.data[i]=t%10000;
        s=t/10000;
    }
    if(s)return -1;
    return 0;
}
int div(hugeint& a,hugeint& b,hugeint& s,hugeint& r)//s=a/b,r=a%b
{
    hugeint temp1=a,temp2=b,temp3=a;
    s.clear();
    while(1)
    {
        temp2=b;
        temp2.inverse();
        temp3=temp1;
        if(!add(temp1,temp2,1))break;
        if(s.inc())return -1;
    }
    r=temp3;
    return 0;
}


#include "hugeint.h"
#define N 1000
void main()
{
    hugeint a(N);
    hugeint b=a,c=a;
    a="300000000";
    b="123432543";
    cout<<a+b<<endl
        <<a-b<<endl
        <<a*b<<endl
        <<a/b<<endl
        <<a%b<<endl;
}

看你程序，是用万进制的，呵呵，万进制的除法可是慢到家了，我曾试过，放弃了，觉的采用百进制比较好,还有，既然用的是C++干嘛不用string呢，这样实现动态的比较容易，我以前也写了个，是十进制的，也贴出来了，在算法与数据结构板块，其中，除法是线性时间，不过代码量太大了，呵呵，当时为了提高时间效率，就对空间睁只眼，闭之眼了

我对这个也不太满意，以后有了时间再改进改进吧。