第八週實驗（四）

* (程序頭部註釋開始)      
* 程序的版權和版本聲明部分      
      
* Copyright (c) 2011, 煙臺大學計算機學院學生      
      
* All rights reserved.      
      
* 文件名稱：分數類中的對象可以和整型數進行四則運算，且運算符合交換律     
      
* 作 者：齊豔紅      
      
 * 完成日期： 2011年 4月 18日      
      
*版 本 號：      
      
 * 對任務及求解方法的描述部分：分數類中的對象可以和整型數進行四則運算，且運算符合交換律       
 *問題描述：在任務3的基礎上拓展。分數類中的對象可以和整型數進行四則運算，且運算符合交換律   
        
 * 程序輸出：      
      
* 程序頭部的註釋結束*/ 
#include <iostream>   
using namespace std;  
class CFraction  
{  
private:  
	int nume;  // 分子   
	int deno;  // 分母   
public:  
	CFraction(int nu=0,int de=1):nume(nu),deno(de){}  
	void simplify();  
	void display();  

	friend CFraction operator+(const CFraction &c1, const CFraction &c2);  //兩個分數相加，結果要化簡   
	friend CFraction operator-(const CFraction &c1, const CFraction &c2);  //兩個分數相減，結果要化簡   
	friend CFraction operator*(const CFraction &c1, const CFraction &c2);  //兩個分數相乘，結果要化簡   
	friend CFraction operator/(const CFraction &c1, const CFraction &c2);  //兩個分數相除，結果要化簡   

	friend CFraction operator+(const CFraction &c, int i);    
	friend CFraction operator+(int i, const CFraction &c );    
	friend CFraction operator-(const CFraction &c, int i);    
	friend CFraction operator-(int i, const CFraction &c );    
	friend CFraction operator*(const CFraction &c, int i);    
	friend CFraction operator*(int i, const CFraction &c );    
	friend CFraction operator/(const CFraction &c, int i);    
	friend CFraction operator/(int i, const CFraction &c );    

	CFraction operator+();  //取正一目運算   
	CFraction operator-();  //取反一目運算   

	friend bool operator>(const CFraction &c1, const CFraction &c2);  //友元函數必須是兩個參數c1，c2
	friend bool operator<(const CFraction &c1, const CFraction &c2);  
	friend bool operator==(const CFraction &c1, const CFraction &c2);  
	friend bool operator!=(const CFraction &c1, const CFraction &c2);  
	friend bool operator>=(const CFraction &c1, const CFraction &c2);  
	friend bool operator<=(const CFraction &c1, const CFraction &c2);  

	friend bool operator>(const CFraction &c, int i);  
	friend bool operator>(int i, const CFraction &c);  
	friend bool operator<(const CFraction &c, int i);  
	friend bool operator<(int i, const CFraction &c);      
	friend bool operator==(const CFraction &c, int i);  
	friend bool operator==(int i, const CFraction &c);    
	friend bool operator!=(const CFraction &c, int i);  
	friend bool operator!=(int i, const CFraction &c);  
	friend bool operator>=(const CFraction &c, int i);  
	friend bool operator>=(int i, const CFraction &c);  
	friend bool operator<=(const CFraction &c, int i);  
	friend bool operator<=(int i, const CFraction &c);  
};  

// 分數化簡   
void CFraction::simplify()  
{  
	int m,n,r;  
	m=abs(deno);  
	n=abs(nume);  
	while(r=m%n)  // 求m，n的最大公約數   
	{  
		m=n;  
		n=r;  
	}  
	deno/=n;     // 化簡   
	nume/=n;  
	if (deno<0)  // 將分母轉化爲正數   
	{  
		deno=-deno;  
		nume=-nume;  
	}  
}  

//顯示分數   
void CFraction::display()  
{  
	cout<<"("<<nume<<"/"<<deno<<")"<<endl;  
}  

// 分數相加   
CFraction operator+(const CFraction &c1, const CFraction &c2)  
{  
	CFraction t;  
	t.nume=c1.nume*c2.deno+c2.nume*c1.deno;  
	t.deno=c1.deno*c2.deno;  
	t.simplify();  
	return t;  
}  

// 分數相減   
CFraction operator-(const CFraction &c1, const CFraction &c2)  
{  
	CFraction t;  
	t.nume=c1.nume*c2.deno-c2.nume*c1.deno;  
	t.deno=c1.deno*c2.deno;  
	t.simplify();  
	return t;  
}  

// 分數相乘   
CFraction operator*(const CFraction &c1, const CFraction &c2)  
{  
	CFraction t;  
	t.nume=c1.nume*c2.nume;  
	t.deno=c1.deno*c2.deno;  
	t.simplify();  
	return t;  
}  

// 分數相除   
CFraction operator/(const CFraction &c1, const CFraction &c2)  
{  
	CFraction t;  
	if (!c2.nume) return c1;  
	t.nume=c1.nume*c2.deno;  
	t.deno=c1.deno*c2.nume;  
	t.simplify();  
	return t;  
}  

CFraction operator+(const CFraction &c, int i)  
{  
	CFraction c1(c.nume+i*c.deno,c.deno);  
	c1.simplify();  
	return c1;  
}  

CFraction operator+(int i, const CFraction &c )  
{  
	CFraction c1(c.nume+i*c.deno,c.deno);  
	c1.simplify();  
	return c1;  
}  

CFraction operator-(const CFraction &c, int i)    
{  
	CFraction c1(c.nume-i*c.deno,c.deno);  
	c1.simplify();  
	return c1;  
}  

CFraction operator-(int i, const CFraction &c )  
{  
	CFraction c1(i*c.deno-c.nume,c.deno);  
	c1.simplify();  
	return c1;  
}  
CFraction operator*(const CFraction &c, int i)  
{  
	CFraction c1(c.nume*i,c.deno);  
	c1.simplify();  
	return c1;  
}  

CFraction operator*(int i, const CFraction &c )  
{  
	CFraction c1(c.nume*i,c.deno);  
	c1.simplify();  
	return c1;  
}  

CFraction operator/(const CFraction &c, int i)  
{  
	CFraction c1(c.nume,c.deno*i);  
	c1.simplify();  
	return c1;  
}  

CFraction operator/(int i, const CFraction &c )  
{  
	CFraction c1(i*c.deno,c.nume);  
	c1.simplify();  
	return c1;  
}  

// 分數取正號   
CFraction CFraction:: operator+()  
{  
	return *this;  
}  

// 分數取負號   
CFraction CFraction:: operator-()  
{  
	CFraction c;  
	c.nume=-nume;  
	c.deno=-deno;  
	return c;       
}  

// 分數比較大小   
bool operator>(const CFraction &c1, const CFraction &c2)  
{  
	int c1_nume,c2_nume,common_deno;  
	c1_nume=c1.nume*c2.deno;        // 計算分數通分後的分子，同分母爲c1.deno*c2.deno   
	c2_nume=c2.nume*c1.deno;   
	common_deno=c1.deno*c2.deno;  
	//if (c1_nume>c2_nume) return true; 無法應對common_deno<0的情形   
	//下面的語句更簡練的一種寫法if ((c1_nume-c2_nume)*common_deno>0) return true;   
	if (c1_nume>c2_nume&&common_deno>0||c1_nume<c2_nume&&common_deno<0) return true; // 將通分後的分子比較大小   
	return false;  
}  

// 分數比較大小   
bool operator<(const CFraction &c1, const CFraction &c2)  
{  
	int c1_nume,c2_nume,common_deno;  
	c1_nume=c1.nume*c2.deno;        
	c2_nume=c2.nume*c1.deno;  
	common_deno=c1.deno*c2.deno;  
	if ((c1_nume-c2_nume)*common_deno<0) return true;   
	return false;  
}  

// 分數比較大小   
bool operator==(const CFraction &c1, const CFraction &c2)  
{  
	if (c1!=c2) return false;  
	return true;  
}  

// 分數比較大小   
bool operator!=(const CFraction &c1, const CFraction &c2)  
{  
	if (c1>c2 || c1<c2) return true;  
	return false;  
}  

// 分數比較大小   
bool operator>=(const CFraction &c1, const CFraction &c2)  
{  
	if (c1<c2) return false;  
	return true;  
}  

// 分數比較大小   
bool operator<=(const CFraction &c1, const CFraction &c2)  
{  
	if (c1>c2) return false;  
	return true;  
}  

bool operator>(const CFraction &c, int i)  
{  
	if(c.deno>0)   
		return c.nume>(i*c.deno);  
	else   
		return c.nume<(i*c.deno);  
}  

bool operator>(int i, const CFraction &c)  
{  
	if(c.deno>0)   
		return (i*c.deno)>c.nume;  
	else   
		return (i*c.deno)<c.nume;  
}  

bool operator<(const CFraction &c, int i)  
{  
	if(c.deno>0)   
		return c.nume<(i*c.deno);  
	else   
		return c.nume>(i*c.deno);  
}  

bool operator<(int i, const CFraction &c)  
{  
	if(c.deno>0)   
		return (i*c.deno)<c.nume;  
	else   
		return (i*c.deno)>c.nume;  
}  

bool operator==(const CFraction &c, int i)  
{  
	return c.nume==(i*c.deno);  
}  

bool operator==(int i, const CFraction &c)  
{  
	return c.nume==(i*c.deno);  
}  

bool operator!=(const CFraction &c, int i)  
{  
	return c.nume!=(i*c.deno);  
}  

bool operator!=(int i, const CFraction &c)  
{  
	return c.nume!=(i*c.deno);  
}  

bool operator>=(const CFraction &c, int i)  
{  
	return !(c<i); //用 !(c<i)符號代替>=
}  

bool operator>=(int i, const CFraction &c)  
{  
	return !(i<c);  
}  

bool operator<=(const CFraction &c, int i)  
{  
	return !(c>i);  
}  

bool operator<=(int i, const CFraction &c)  
{  
	return !(i>c);  
}  

int main()  
{  
	CFraction x(1,3),y(-5,10),s;  
	cout<<"兩個分數爲：x=1/3 ，y=-5/10"<<endl;  
	s=+x+y;  
	cout<<"分數相加及取正爲："<<"+x+y=";  
	s.display();  
	s=x-y;  
	cout<<"分數相減爲："<<"x-y=";  
	s.display();  
	s=x*y;  
	cout<<"分數相乘爲："<<"x*y=";  
	s.display();  
	s=x/y;  
	cout<<"分數相除爲："<<"x/y=";  
	s.display();  
	s=-x+y;  
	cout<<"分數取負爲："<<"-x+y=";  
	s.display();  
	x.display();  
	if (x>y) cout<<"大於"<<endl;  
	if (x<y) cout<<"小於"<<endl;  
	if (x==y)cout<<"等於"<<endl;  
	y.display();  
	cout<<endl;  
	system("pause");  
	return 0;  
}  

總結：這個程序還是有點迷糊滴，具體的探究還得繼續，現在得保持不弄明白不罷休的態度學習纔行啊！