/ StrInt + - * /(整除) % (取模)
//==================
===================
#ifndef STRINT_HEADER
#define STRINT_HEADER
#include<iostream>
using namespace std;
//-------------------------------------
class StrInt{
enum { BYTENUM = 200 };
string _sign;
string _num;
public:
StrInt(const string& a = string("0") );
StrInt(const string& sign, const string& num);
friend StrInt mul( const StrInt& a, const StrInt& b );
friend StrInt add( const StrInt& a, const StrInt& b );
friend StrInt sub( const StrInt& a, const StrInt& b );
friend StrInt div( const StrInt& a, const StrInt& b );
friend StrInt mod( const StrInt& a, const StrInt& b );
friend istream& operator>>(istream& in, StrInt& a);
friend ostream& operator<<(ostream& out, const StrInt& a);
};//-----------------------------------
#endif // STRINT_HEADER