高精度运算（运算符重载）

终于写好了哇，我的亲娘来，满满的都是泪啊。。。重载你妹啊。。。。。

#include <iostream>
#include <string.h>
using namespace std;
const int Base=1000000000;
const int Capacity=100;
typedef long long huge;

struct BigInt
{
    int Len;
    int Data[Capacity];
    BigInt() : Len(0) {}
    BigInt (const BigInt &V) : Len(V.Len)
    {
        memcpy (Data, V.Data, Len*sizeof*Data);
    }
    BigInt(int V) : Len(0)
    {
        for(; V>0; V/=Base) Data[Len++]=V%Base;
    }
    BigInt &operator=(const BigInt &V)
    {
        Len=V.Len;
        memcpy(Data, V.Data, Len*sizeof*Data);
        return *this;
    }
    int &operator[] (int Index)
    {
        return Data[Index];
    }
    int operator[] (int Index) const
    {
        return Data[Index];
    }
};
int compare(const BigInt &A, const BigInt &B)
{
    if(A.Len!=B.Len) return A.Len>B.Len ? 1:-1;
    int i;
    for(i=A.Len-1; i>=0 && A[i]==B[i]; i--);
    if(i<0)return 0;
    return A[i]>B[i] ? 1:-1;
}

BigInt operator + (const BigInt &A,const BigInt &B)
{
    int i,Carry(0);
    BigInt R;
    for(i=0; i<A.Len||i<B.Len||Carry>0; i++)
    {
        if(i<A.Len) Carry+=A[i];
        if(i<B.Len) Carry+=B[i];
        R[i]=Carry%Base;
        Carry/=Base;
    }
    R.Len=i;
    return R;
}

BigInt operator - (const BigInt &A,const BigInt &B)
{
    int i,Carry(0);
    BigInt R;
    R.Len=A.Len;
    for(i=0; i<R.Len; i++)
    {
        R[i]=A[i]-Carry;
        if(i<B.Len) R[i]-=B[i];
        if(R[i]<0) Carry=1,R[i]+=Base;
        else Carry=0;
    }
    while(R.Len>0&&R[R.Len-1]==0) R.Len--;
    return R;
}

BigInt operator * (const BigInt &A,const BigInt &B)
{
    int i;
    huge Carry(0);
    BigInt R;
    for(i=0; i<A.Len||Carry>0; i++)
    {
        if(i<A.Len) Carry+=huge(A[i])*B[i];
        R[i]=Carry%Base;
        Carry/=Base;
    }
    R.Len=i;
    return R;
}
istream &operator>>(istream &In,BigInt &V)
{
    char Ch;
    for(V=0; In>>Ch;)
    {
        V=V*10+(Ch-'0');
        if(In.peek()<=' ') break;
    }
    return In;
}
ostream &operator<<(ostream &Out,const BigInt &V)
{
    int i;
    Out<<(V.Len==0 ? 0:V[V.Len-1]);
    for(i=V.Len-2; i>=0; i--) for(int j=Base/10; j>0; j/=10) Out<<V[i]/j;
    return Out;
}
int main()
{
    BigInt a,b;
    cin>>a>>b;
    cout<<"+"<<endl;
    cout<<a+b<<endl;
    if(compare(a, b)>0) cout<<"-"<<endl<<a-b<<endl;
    else cout<<"-"<<endl<<b-a<<endl;
    cout<<"*"<<endl<<a*b<<endl;
}