傻算的计算器 多年前的课堂作业 比较简单
class Fraction;
bool operator>(int n,Fraction &c);
bool operator>(Fraction &c,Fraction &f);
bool operator>=(int n,Fraction &c);
bool operator>=(Fraction &c,Fraction &f);
bool operator==(int n,Fraction &c);
bool operator==(Fraction &c,Fraction &f);
bool operator!=(Fraction &c,Fraction &f);
bool operator!=(int n,Fraction &c);
bool operator<=(Fraction &c,Fraction &f);
bool operator<=(int n,Fraction &c);
bool operator<(Fraction &c,Fraction &f);
bool operator<(int n,Fraction &c);
Fraction operator-(int n,Fraction &c);
ostream&operator<>(istream& input,Fraction& f);
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