qq.h

/*
 * bigDecimal.h
 */

#ifndef BIGDECIMAL_H_
#define BIGDECIMAL_H_
#include <iostream>
#include <string>
#include <sstream>

using namespace std;

struct Node {
  char data;
  Node* next;
};

class BigDecimal {
public:
	BigDecimal();
	BigDecimal(const char* str);
	BigDecimal(int i);
	BigDecimal(float f);
	BigDecimal(double d);
	BigDecimal(const BigDecimal& bi);
	~BigDecimal();

	/* #### You need to implement from_string(const char*) and to_string(char*) methods. #### */
	/**
	 * Method: void from_string(const char* str)
	 * Description:
	 * 		from_string method will read the number from str.
	 * 		If str is valid, it will be parsed and stored into sign and storage, and then return true. Otherwise, false will be returned.
	 */
	bool from_string(const char* str);

	/**
	 * Method: void to_string(const char* str)
	 * Description:
	 * 		to_string method will output the current number to str.
	 */
	void to_string(char* str);

	/* #### Please add your overloading methods below. #### */
    BigDecimal operator+(BigDecimal& b1);
    BigDecimal operator+(double& b1);
    // miss double + big

    BigDecimal operator-(BigDecimal& b1);
    BigDecimal operator-(double& b1);
    //BigDecimal operator-(const BigDecimal& b1);

    BigDecimal operator*(BigDecimal& b1);
    BigDecimal operator*(double& b1);
    //BigDecimal operator*(const BigDecimal& b1);

    BigDecimal operator/(BigDecimal& b1);
    BigDecimal operator/(double& b1);
    //BigDecimal operator/(const BigDecimal& b1);

    BigDecimal& operator=(BigDecimal& b);
    BigDecimal& operator=(double& d);
    BigDecimal& operator=(int& i);
    BigDecimal& operator=(float& f);

    BigDecimal& operator++();
    BigDecimal operator++(int i);

    BigDecimal& operator--();
    BigDecimal operator--(int i);

    bool operator>(BigDecimal& b1);
    bool operator>(double& b1);
    bool operator>(int& b1);
    bool operator>(float& b1);

    bool operator>=(BigDecimal& b1);
    bool operator>=(double& b1);
    bool operator>=(int& b1);
    bool operator>=(float& b1);

    bool operator<(BigDecimal& b1);
    bool operator<(double& b1);
    bool operator<(int& b1);
    bool operator<(float& b1);

    bool operator<=(BigDecimal& b1);
    bool operator<=(double& b1);
    bool operator<=(int& b1);
    bool operator<=(float& b1);

    bool operator==(BigDecimal& b1);
    bool operator==(double& b1);
    bool operator==(int& b1);
    bool operator==(float& b1);

    bool operator!=(BigDecimal& b1);
    bool operator!=(double& b1);
    bool operator!=(int& b1);
    bool operator!=(float& b1);

    BigDecimal operator^(BigDecimal& b);

    istream& operator>>(BigDecimal& b);
    ostream& operator<<(const BigDecimal& b);

    // helper functions
    Node* linkedListFromStr(const string str);
    Node* linkedListFromChar(const char* str);


private:
	Node* linkedList;

};



#endif