问题描述

编译时出现这样的错误，求大神指点解决方法

程序如下：
#include
using namespace std;
class zrf_Ratio;
zrf_Ratio operator+(const zrf_Ratio& r1 const zrf_Ratio& r2);
zrf_Ratio operator-(const zrf_Ratio& const zrf_Ratio&);
zrf_Ratio operator*(const zrf_Ratio& const zrf_Ratio&);
zrf_Ratio operator/(const zrf_Ratio& const zrf_Ratio&);

class zrf_Ratio
{
public:
zrf_Ratio(){}
zrf_Ratio(int r1int r2):num(r1)den(r2){}
zrf_Ratio f1(zrf_Ratio& z)
{
int rm=z.numn=z.den;
while(r=z.num%z.den)
{
z.num=z.den;
z.den=r;
}
r=z.den;
z.num=m/r;
z.den=n/r;
return z;
}
friend ostream& operator<<(ostream& ostr const zrf_Ratio& r)
{ return ostr << r.num << ""/"" << r.den;}

zrf_Ratio operator-(const zrf_Ratio& r1){return f1(zrf_Ratio(num*r1.den-r1.num*denden*r1.den));}friend zrf_Ratio operator+(const zrf_Ratio& r1 const zrf_Ratio& r2){    zrf_Ratio a;    return a.f1(zrf_Ratio(r1.num*r2.den+r2.num*r1.denr1.den*r2.den));}friend zrf_Ratio operator-(const zrf_Ratio& r1 const zrf_Ratio& r2){    zrf_Ratio a;    return a.f1(zrf_Ratio(r1.num*r2.den-r2.num*r1.denr1.den*r2.den));}friend zrf_Ratio operator*(const zrf_Ratio& r1 const zrf_Ratio& r2){    zrf_Ratio a;    return a.f1(zrf_Ratio(r1.num*r2.numr1.den*r2.den));}friend zrf_Ratio operator/(const zrf_Ratio& r1 const zrf_Ratio& r2){    zrf_Ratio a;    return a.f1(zrf_Ratio(r1.num*r2.denr1.den*r2.num));}

private:
int numden;
};
int mian()
{
zrf_Ratio x(37)y(49)z;
z=x.operator-(y);
cout<<""x-y=""<<z<<endl;
z=x+y;
cout<<""x+y=""<<z<<endl;
z=x-y;
cout<<""x-y=""<<z<<endl;
z=x*y;
cout<<""x*y=""<<z<<endl;
z=x/y;
cout<<""x/y=""<<z<<endl;
return 0;
}
显示错误如下：
Deleting intermediate files and output files for project '2 - Win32 Debug'.
--------------------Configuration: 2 - Win32 Debug--------------------
Compiling...
2.cpp
Linking...
LIBCD.lib(crt0.obj) : error LNK2001: unresolved external symbol _main
Debug/2.exe : fatal error LNK1120: 1 unresolved externals
执行 link.exe 时出错.

2.exe - 1 error(s) 0 warning(s)

解决方案

main拼写错了

解决方案二：
main拼写错误。。。