高精度运算（运算符重载）(一)

[cpp]
#include
#include
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; i0; i++)
{
if(i if(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[i]=A[i]-Carry;
if(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; i0; i++)
{
if(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< return Out;
}
int main()
{
BigInt a,b;
cin>>a>>b;
cout<<"+"< cout< if(compare(a, b)>0) cout<<"-"< else cout<<"-"< cout<<"*"< }

#include
#include
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; i0; i++)
{
if(i if(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[i]=A[i]-Carry;
if(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