C++程序—分数的加减乘除

//这是分数操作类的定义代码：保存为Fraction.h文件
#include
#include
#include

class Fraction
{
public:
Fraction();
friend const Fraction operator +(const Fraction& lhs,const Fraction& rhs);
friend const Fraction operator - (const Fraction& lhs,const Fraction& rhs);
friend const Fraction operator / (const Fraction& lhs,const Fraction& rhs);
friend const Fraction operator * (const Fraction& lhs,const Fraction& rhs);
long Gcd(long num,long deno);//求最大公约数
void Print();//输出函数
void Simplify();//分数化简
void Read();
int StrIndex(char s[],int pos,char t);
char * SubString(char sub[],char s[],unsigned int pos,unsigned int len);

private:
double numerator;//分子
double denominator;//分母
char arr[50];
char arr1[50];
char arr2[50];
};

Fraction::Fraction()
{
this->numerator = 1;
this->denominator = 1;
}

const Fraction operator+(const Fraction& lhs,const Fraction& rhs)
{
Fraction newFrac;

if(lhs.denominator == 0 || rhs.denominator == 0)
{
cout<<"存在分母为0的分数"< exit(-1);
}
newFrac.numerator = (lhs.numerator * rhs.denominator) + (rhs.numerator * lhs.denominator);
newFrac.denominator = lhs.denominator * rhs.denominator;

newFrac.Simplify();
return newFrac;
}

const Fraction operator -(const Fraction& lhs,const Fraction& rhs)
{
Fraction newFrac;

if(lhs.denominator == 0 || rhs.denominator == 0)
{
cout<<"存在分母为0的分数"< exit(-1);
}

newFrac.numerator = rhs.denominator * lhs.numerator - rhs.numerator * lhs.denominator;
newFrac.denominator = lhs.denominator * rhs.denominator;

newFrac.Simplify();
return newFrac;
}

const Fraction operator *(const Fraction &lhs,const Fraction &rhs)
{
if((lhs.denominator * rhs.denominator) == 0)
{
cout<<"存在分母为零的分数"< exit(-1);
}
else
{
Fraction newFrac;
newFrac.denominator = lhs.denominator * rhs.denominator;
newFrac.numerator = lhs.numerator * rhs.numerator;
newFrac.Simplify();
return newFrac;
}
}

const Fraction operator /(const Fraction& lhs,const Fraction& rhs)
{
if(rhs.denominator == 0 || lhs.denominator == 0|| rhs.numerator == 0)
{
cout<<"存在分母为零的分数或者存在分母被除数为零，请检查算式"< exit(-1);
}

Fraction newFrac;
if(lhs.numerator== 0)
{
newFrac.denominator = 1;
newFrac.numerator = 0;
return newFrac;
}

newFrac.denominator = lhs.denominator * rhs.numerator;
newFrac.numerator = lhs.numerator * rhs.denominator;

newFrac.Simplify();
return newFrac;
}

void Fraction::Print()
{
if(this->numerator == 0)
{
cout << "0"< }
else
{
cout<< this->numerator<<"/"<denominator< }
return ;
}

long Fraction::Gcd(long num,long deno)
{//求最大公约数
long tmp;
while(deno != 0)
{
tmp = num%deno;
num = deno;
deno = tmp;
}

return num;
}

void Fraction::Simplify()
{//分数化简
long tmp = 0;
tmp = Gcd((long)this->numerator,(long)this->denominator);
this->denominator /= tmp;
this->numerator /= tmp;
return ;
}

//操作符的定位函数
int Fraction::StrIndex(char s[],int pos,char t)
{
int ii=0,j=0,slen=0;
slen=strlen(s);
ii=pos;
j=0;
while(ii for(int k=0;k if(s[k]==t)
{
ii++;
j++;
break;
}
else
{
ii=ii-j+1;
j=0;
}
if(j>=1) return ii-j;
else return 0;
}

void Fraction::Read()
{
int loc1=0,loc2=0,loc3=0,temp1=0,temp2=0,temp3=0;
int flag=1;
char choose;
Fraction p1,p2,res;
long sum1=0,sum2=0,sum3=0,sum4=0;
while(flag)
{
double sum1=0,sum2=0,sum3=0,sum4=0;
cout<<"请输入一个数学表达式："< cin>>arr;
int len1=strlen(arr);
//定位操作符函数的调用
loc1=StrIndex(arr,1,'+');
if(loc1==0)
{
loc1=StrIndex(arr,1,'-');
if(loc1==0)
{
loc1=StrIndex(arr,1,'*');
if(loc1==0)//三个'/'情况下的操作符'/'的定位
{
loc1=StrIndex(arr,1,'/');
temp1=loc1;
loc1=StrIndex(arr,loc1+1,'/');temp2=loc1;
loc1=StrIndex(arr,loc1+1,'/');temp3=loc1;
if(temp1 else loc1=temp1;
}
}
}
//定位前一个'/'
loc2=StrIndex(arr,1,'/');
//定位后一个'/'
loc3=StrIndex(arr,loc1+1,'/');

//提取两个分数的分子分母
SubString(p1.arr1,arr,0,loc2-1);//前一个分子位数
SubString(p1.arr2,arr,loc2,loc1-loc2-1);//前一个分母位数
SubString(p2.arr1,arr,loc1,loc3-loc1-1);//后一个分子位数
SubString(p2.arr2,arr,loc3,len1-loc3);//后一个分母位数
//分子分母化为十进制数(分子分母为多位数的情况)
for(int i=0;i sum1=(p1.arr1[i]-48)*pow(10,loc2-2-i)+sum1;
p1.numerator=sum1;
for(int j=0;j sum2=(p1.arr2[j]-48)*pow(10,loc1-loc2-2-j)+sum2;
p1.denominator=sum2;
for(int k=0;k sum3=(p2.arr1[k]-48)*pow(10,loc3-loc1-2-k)+sum3;
p2.numerator=sum3;
for(int l=0;l sum4=(p2.arr2[l]-48)*pow(10,len1-loc3-1-l)+sum4;
p2.denominator=sum4;

cout<<"数学表达式的结果为"< cout<
switch(arr[loc1-1])
{
case '+':res=p1+p2;res.Print();break;
case '-':res=p1-p2;res.Print();break;
case '*':res=p1*p2;res.Print();break;
case '/':res=p1/p2;res.Print();break;
default:break;
}
cout<<"还要继续吗?(y/n)"< cin>>choose;
if(choose=='y'||choose=='Y') flag=1;
else flag=0;
}
}

char * Fraction::SubString(char sub[],char s[],unsigned int pos,unsigned int len)
{
if( pos<0 || pos>strlen(s) || len<1 || len>strlen(s)-pos )//strlen返回的是无符号数，用无符号数比较就不产生警告
return NULL;
else
{
for(unsigned int i=0;i sub[i]=s[i+pos];
return sub;
}
}

//这是测试代码：
#include
#include
#include "Fraction.h"
#include
#include

void main()
{
Fraction r;
r.Read();
}

//这是测试数据：
1/2+3/4=5/4
12/34+56/78=710/663
123/456+789/1234=85261/93784
1234/4567+1357/2468=0.82

1/2-3/4=-1/4
12/34-56/78=-242/663
123/456-789/1234=-34667/93784
1234/4567-1357/2468=-0.2796

1/2*3/4=3/8
12/34*56/78=56/221
123/456*789/1234=32349/187568
1234/4567*1357/2468=1357/9134

1/2/3/4=2/3
12/34/56/78=117/238
123/456/789/1234=25297/59964
1234/4567/1357/2468=0.49142

//类的头文件fclass.hclass fraction
{
private:
int nr; //分子
int dn; //分母
public:
fraction input();
fraction operator +(fraction &);
fraction operator -(fraction &);
fraction operator *(fraction &);
fraction operator /(fraction &);
void output(); //输出约分后的分数
void output1(); // 输出普通分数
}; //实现文件fclass.cpp#include
#include"fclass.h"
fraction fraction::operator+(fraction &a)
{
fraction g;
g.dn=dn*a.dn;
g.nr=nr*a.dn+a.nr*dn;
return g;
}
fraction fraction::operator-(fraction &a)
{
fraction g;
g.dn=dn*a.dn;
g.nr=nr*a.dn-a.nr*dn;
return g;
}
fraction fraction::operator*(fraction &a)
{
fraction g;
g.dn=dn*a.dn;
g.nr=nr*a.nr;
return g;
}
fraction fraction::operator/(fraction &a)
{
fraction g;
g.dn=dn*a.nr;
g.nr=nr*a.dn;
return g;
}
fraction fraction::input()
{
fraction a;
cin>>a.nr>>a.dn;
return a;
}
void fraction::output()
{
int i;
if(dn==0)
cout<<"error"< else
if(nr%dn==0)
cout< else
{
for(i=2;i<=nr||i<=dn;)
{
if(nr%i==0&&dn%i==0)
{
nr=nr/i;
dn=dn/i;
i=2;
}
else
i++;
}
cout< }
}
void fraction::output1()
{
cout<}
//主程序#include
#include"fclass.h"
void menu()
{
cout<<"=================================================="< cout<<"1-输入2个新的分数，可进行如下运算:"< cout<<"2-加法"< cout<<"3-减法"< cout<<"4-乘法"< cout<<"5-除法"< cout<<"6-退出"< cout<<"=================================================="<}void main()
{
void menu();
int m;
bool flag=true;
fraction s1,s2,s3;
while(flag)
{ menu();
cin>>m;
switch(m)
{
case 1:
cout<<"请按照如下方式输入2个分数: 分子/分母"< s1=s1.input();
s2=s2.input();
cout<<"请输入你要进行的计算:"< break;
case 2:
s3=s1+s2;
s1.output1();
cout<<" + ";
s2.output1();
cout<<"=";
s3.output();
break;
case 3:
s3=s1-s2;
s1.output1();
cout<<" - ";
s2.output1();
cout<<"=";
s3.output();
break;
case 4:
s3=s1*s2;
s1.output1();
cout<<" * ";
s2.output1();
cout<<"=";
s3.output();
break;
case 5:
s3=s1/s2;
s1.output1();
cout<<" / ";
s2.output1();
cout<<"=";
s3.output();
break;
case 6:
flag=false;
break;
default:
break;
}
}
}