大数加减乘除---C++运算符重载

#include <iostream>
#include <typeinfo>
#include <string>
#include <vector>
#include <iterator>
using namespace std;
template<typename T>
void _swap(T &a, T &b)
{
	T tmp = T();
	tmp = a;
	a = b;
	b = tmp;
}
class BigData
{
public:
	//0初始化
	BigData(){}         
	BigData(const char *src);
	BigData(bool flag,int size);
	BigData(int data);
	BigData(vector<int>& src);
	BigData(string &src);
	BigData operator =(const BigData &data);
	BigData(const BigData&data);
	BigData(bool sign,const BigData&data);
	bool operator >(const BigData &data) const;
	bool operator <(const BigData &data) const;
	bool operator ==(const BigData &data) const;
	bool operator !=(const BigData &data) const;
	bool operator >=(const BigData &data) const;
	bool operator <=(const BigData &data) const;
	BigData operator -();               //取反运算符
	BigData operator+(const BigData &src);
	BigData operator-(const BigData &src); 	
	BigData operator *(const BigData &data);
	BigData operator /(const BigData &data);
	BigData operator +=(const BigData &daat);
	BigData operator -=(const BigData &data);
	BigData operator *=(const BigData &daat);
	BigData operator /=(const BigData &data);
	BigData operator ++();   //前置++
	BigData operator --();
	BigData operator ++(int);//后置++
	BigData operator --(int);
	void show()
	{
		if (_data.size() == 0)
		{
			cout <<"0"<<endl;
			return;
		}
		if (!_sign)
		{
			cout << "-";
		}
		copy(_data.rbegin(), _data.rend(), ostream_iterator<int>(cout, ""));
		cout << endl;
	}
private:
	vector<int> _data;
	bool _sign;
};
BigData::BigData(const char *src)
{
	_sign = true;
	if (src[0] == '-')
	{
		_sign = false;
	}	
	int len = strlen(src);
	int min = 0;
	if (!_sign)
	{
		min = 1;
	}
	for (int i = len - 1; i >= min; i--)
	{
		if (src[i] == '-' && i == 0)
		{
			_sign = false;
			break;
		}
		_data.push_back(src[i] - '0');
	}
}
BigData::BigData(int data)
{
	if (data < 0)
	{
		_sign = false;
	}
	else
	{
		_sign = true;
	}

	int tmp = 0;
	while (data)
	{
		tmp = data % 10;        //从低位到高位得到每一位数字
		_data.push_back(tmp);   //存入每一位数字
		data /= 10;
	}
	cout << "succeed" << endl;
}
BigData::BigData(bool sign,const BigData &data)
{
	this->_sign = sign;
	_data = data._data;
	cout << "succeed" << endl;
}
BigData::BigData(bool flag, int size)
{
	_sign = flag;
	while (size > 0)
	{
		_data.push_back(0);
		size--;
	}
}
BigData::BigData(vector<int>& src)
{
	_sign = true;
	_data = src;
	cout << "succeed" << endl;
}
BigData::BigData(const BigData &data)
{
	this->_sign = data._sign;
	_data = data._data;
	cout << "succeed" << endl;
}
BigData::BigData(string &src)
{
	_sign = true;
	int len = src.size();
	for (int i = len - 1; i >= 0; i--)
	{
		if (src[i] == '-' && i == 0)
		{
			_sign = false;
			break;
		}
		_data.push_back(src[i] - '0');
	}
}
BigData BigData::operator+(const BigData &src)
{
	BigData num1 = *this;
	BigData num2 = src;
	if (_sign == true && src._sign == false)//正+负---正-(-负)
	{
		num2 = -num2;
		return num1 - num2;
	}
	if (_sign == false && src._sign == true)//负+正---正-(-负)
	{
		num1 = -num1;
		return num2 - num1;
	}     
	
	//正正,负负
	vector<int>::iterator it1 = num1._data.begin();
	vector<int>::iterator it2 = num2._data.begin();
	BigData tmp;
	int add = 0;
	for (; it1 != num1._data.end() && it2 != num2._data.end();it1++, it2++)
	{
		tmp._data.push_back((*it1 + *it2 + add) % 10);
		add = (*it1 + *it2 + add) / 10;
	}

	while (it1 != num1._data.end())
	{
		tmp._data.push_back(*it1++ + add);
		add = 0;
	}
	while (it2 != num2._data.end())
	{
		tmp._data.push_back(*it2++ + add);
		add = 0;
	}
	tmp._sign = this->_sign;

	return tmp;
}
BigData BigData::operator-(const BigData &src)
{
	BigData num1 = *this;
	BigData num2 = src;
	BigData tmp;
	if (_sign == true && src._sign == false)    //正-负---正+(-负)
	{
		num2 = -num2;
		return num1 + num2;
	}
	if (_sign == false && src._sign == true)    //负-正---负+(-正)
	{
		num2 = -num2;
		return num1 + num2;
	}
	if (_sign == false && src._sign == false)
	{
		if (num1 < num2)    //
		{
			BigData temp(false, (-num1) - (-num2));
			return temp;
		}
		if (num1 > num2)
		{
			BigData temp(true, (-num2) - (-num1));
			return temp;
		}
		else
		{
			return tmp;
		}
	}
	if (_sign == true && src._sign == true)
	{
		if (num1 < num2)    //
		{
			BigData temp(false, (num2 - num1));    //正正
			return temp;
		}
	}
	bool flag = true;
	vector<int>::iterator it1 = num1._data.begin();
	vector<int>::iterator it2 = num2._data.begin();
	tmp._sign = flag;

	int add = 0;
	for (; it1 != num1._data.end() && it2 != num2._data.end();
		it1++, it2++)
	{
		tmp._data.push_back((*it1 - *it2 ));
	}

	while (it1 != num1._data.end())
	{
		tmp._data.push_back(*it1++);
		add = 0;
	}
	for (unsigned int i = 0; i < tmp._data.size() - 1; i++ )
	{
		if (tmp._data[i] < 0)
		{
			tmp._data[i] += 10;
			tmp._data[i + 1] --;
		}
	}
	tmp._sign = this->_sign;
	return tmp;
}
bool BigData::operator >(const BigData &data) const
{
	cout << "bool BigData::operator >(const BigData &data) const"<<endl;
	if (this->_sign != data._sign) //符号不同
	{
		return _sign > data._sign;
	}   
	if (this->_data.size() > data._data.size()) //符号相同,且this长
	{
		if (this->_sign == true)
		{
			return true;
		}
		else
		{
			return false;
		}
	}
	if (this->_data.size() < data._data.size())//符号相同,且this短
	{
		if (this->_sign == true)
		{
			return false;
		}
		else
		{
			return true;
		}
	}
	for (int i = _data.size() - 1; i >=0; i--) //符号相同,长度相同
	{
		if (_data[i] > data._data[i])
		{
			if (this->_sign == true)
			{
				return true;
			}
			else
			{
				return false;
			}
		}
		else if (_data[i] < data._data[i])
		{
			if (this->_sign == true)
			{
				return false;
			}
			else
			{
				return true;
			}
		}
	}
	return false;
}
bool BigData::operator <(const BigData &data) const
{
	cout <<"bool BigData::operator <(const BigData &data) const"<< endl;
	if (!(*this > data) && !(*this == data))
	{
		return true;
	}
	return false;
}
bool BigData::operator ==(const BigData &data) const
{
	cout <<"bool BigData::operator ==(const BigData &data) const"<< endl;
	if (this->_data == data._data && this->_sign == data._sign)
	{
		return true;
	}
	return false;
}
bool BigData::operator !=(const BigData &data) const
{
	cout <<"bool BigData::operator !=(const BigData &data) const"<< endl;
	if (!(*this == data))
	{
		return true;
	}
	return false;
}
bool BigData::operator >=(const BigData &data) const
{
	cout <<"bool BigData::operator >=(const BigData &data) const"<< endl;
	if (*this > data || *this == data)
	{
		return true;
	}
	return false;
}
bool BigData::operator <=(const BigData &data) const
{
	if (!(*this > data))
	{
		return true;
	}
	return false;
}
BigData BigData::operator =(const BigData &data)
{
	cout <<"BigData BigData::operator =(const BigData &data)"<<endl;
	this->_sign = data._sign;
	this->_data = data._data;
	return *this;
}
BigData BigData::operator -()      //改变了BigData对象的符号
{
	this->_sign = !this->_sign;
	return *this;
}
BigData BigData::operator *(const BigData &data)
{
	BigData num1(*this);
	BigData num2(data);
	int len1 = num1._data.size();
	int len2 = num2._data.size();
	int size = len1 * len2;
	bool sign = true;
	if (num1._sign == true && num2._sign == false)
	{
		sign = false;
	}
	if (num1._sign == false&&num2._sign == true)
	{
		sign = false;
	}
	BigData tmp(sign,size);
	for (int i = 0; i < len1; i++)
	{
		for (int j = 0; j < len2; j++)
		{
			tmp._data[i + j] += num1._data[i] * num2._data[j];
		}
	}
	for (unsigned int i = 0; i < tmp._data.size()-1; i++)
	{
		if (tmp._data[i] >= 10)
		{
			tmp._data[i + 1] += tmp._data[i] / 10;
			tmp._data[i] %= 10;
		}
	}
	while (tmp._data.size() > 1 && tmp._data[tmp._data.size() - 1] == 0)
	{
		tmp._data.erase(tmp._data.end()-1);
	}
	return tmp;
} 
BigData BigData::operator /(const BigData &data)
{
	BigData tmp;
	BigData num1 = *this;
	BigData num2 = data;
	if (num1 == num2)
	{
		tmp._data.push_back(1);
		tmp._sign = true;
	}
	if (num1._sign == false && num2._sign == false)
	{
		if (num1 > num2)
		{
			return  tmp;
		}
		num1 = -num1;
		num2 = -num2;
		BigData temp = num1/ num2;
		return temp;
	}
	if (num1._sign == true && num2._sign == true)
	{
		if (num1 < num2)
		{
			return tmp;
		}
		tmp._sign = true;
	}
	if (num1._sign == false)
	{
		
		num1 = -num1;
		BigData temp(false, num1 / num2);
		return temp;
	}
	if (num2._sign == false)
	{
		
		num2 = -num2;
		BigData temp (false,num1 / num2);
		return temp;
	}
	BigData zoro(0);
	zoro._sign = true;
	BigData one(1);
	one._sign = true;
	int len = num1._data.size();
	BigData temp(len,tmp._sign);
	tmp = temp;
	while ((num1 = (num1 - num2)) >= zoro)
	{
		tmp += one;
	}
	return tmp;
}
BigData BigData::operator +=(const BigData &data)
{
	*this = *this + data;
	return *this;
}
BigData BigData::operator -=(const BigData &data)
{
	*this = *this - data;
	return *this;
}
BigData BigData::operator *=(const BigData &data)
{
	*this = *this * data;
	return *this;
}
BigData BigData::operator /=(const BigData &data)
{
	*this = *this / data;
	return *this;
}
BigData BigData::operator ++()
{
	BigData one(1);
	*this += one;
	return *this;
}
BigData BigData::operator --()
{
	BigData one(1);
	*this -= one;
	return *this;
}
BigData BigData::operator ++(int)
{
	BigData temp(*this);
	BigData one(1);
	*this += one;
	return temp;
}
BigData BigData::operator --(int)
{
	BigData temp(*this);
	BigData one(1);
	*this -= one;
	return temp;
}
int main()
{
	
	BigData data1(12442);         //int类型构造BigData对象
	vector<int> d({ 2,3,2,3,4,5,6,7,5,3,2,4,4,5,6,7,5,3,4,2,5,6 });
	BigData data2 = d;            //vector<int>类型构造BigData对象
	BigData data3("1234565346634436");         //const char*类型构造BigData对象
	BigData data4("6543216433333333333333333");//const char*类型构造BigData对象
	string dt = "-134423546";
	BigData data5(dt);                         //string类型构造BigData对象           
	BigData data = data3 + data4;              //data3调用+方法,data4是参数
	BigData data6 = data3 - data4;
	BigData data8("-12"); 
	BigData data9("24");
	data = data3 - data4 - data9;
	data.show();
	data = data8 - data9 - data9;
	data.show();
	data = data8 * data9 * data8;
	data.show();
	data = data9 / data8;
	data.show();
	data++;
	data.show();
	data6.show();
	return 0;
}