es10.4

#include<iostream>

namespace Numbers {

    struct Rational{
        int numerator;
        int denominator;

        Rational(int num=0, int den=1);
    };

    Rational add(Rational a, Rational b);

    Rational sub(Rational a, Rational b);

    Rational mul(Rational a, Rational b);

    Rational div(Rational a, Rational b);

    Rational reduce(Rational a);

    bool less(Rational a, Rational b);

    std::ostream & operator<<(std::ostream & s, Rational & r);
}


















#include <iostream>
#include "rational.h"

using namespace std;

namespace Numbers {
    // Inserire il codice che implementa le funzioni definite in "rational.h"

    Rational::Rational(int num,int den){
        if(num==0){
            if(den<=0){
                numerator=0;
                denominator=0;
            }
            else{
            numerator=0;
            denominator=1;//
         };
        }
        else{
        if(den==0){
            numerator=0;
            denominator=0;
        }
        else if(den<=0){
        numerator=num*(-1);
        denominator=den*(-1);
        }
        else if(den>0){
            numerator=num;
            denominator=den;
        }
      };
    };

    Rational add(Rational a, Rational b){
        int num=a.numerator*b.denominator+a.denominator*b.numerator;
        int den=a.denominator*b.denominator;
        if(den==0)
        return Rational(0,0);
        else
        return Rational(num,den);
    };

    Rational sub(Rational a, Rational b){
        int num=a.numerator*b.denominator-a.denominator*b.numerator;
        int den=a.denominator*b.denominator;
        if(den==0)
        return Rational(0,0);
        else
        return Rational(num,den);
    };

    Rational mul(Rational a, Rational b){
        int num=a.numerator*b.numerator;
        int den=a.denominator*b.denominator;
        if(den==0)
        return Rational(0,0);
        else
        return Rational(num,den);
    };

    Rational div(Rational a, Rational b){
        int num=a.numerator*b.denominator;
        int den=a.denominator*b.numerator;
        if(den==0)
        return Rational(0,0);
        else
        return Rational(num,den);
    };

     Rational reduce(Rational a){
   int num=a.numerator;
   int den=a.denominator;

 //  if(num==0)
 //  return Rational(0,den);
  // else{
   if(den>0){
   int i=2;
   while(i<10){
       if(num%i==0 && den%i==0){
           num=num/i;
           den=den/i;
       }
       else
       i++;
   }

    return Rational(num,den);
    }
    else
    return Rational(0,0);
  //   }

    };

    std::ostream & operator<<(std::ostream & s, Rational & r){
        s<<r.numerator<<'/'<<r.denominator;

        return s;

    };

    bool less(Rational a, Rational b){ //if   Rational a < Rational b
       bool chek=true;
        if(a.denominator==b.denominator){
            if(a.numerator<b.numerator)
            chek=true;
            else
            chek=false;
        }

        else if(a.numerator==b.numerator){
            if(a.denominator>b.denominator)
            chek=true;
            else
            chek=false;
        }

        else if(a.denominator!=b.denominator){
         int num1=a.numerator*b.denominator;
         int num2=b.numerator*a.denominator;
         if(num1<num2)
         chek=true;
         else
         chek=false;

        }
        return chek;
    };
}





















#include "rational.h"


using namespace std;
using namespace Numbers;
//
int main()
{
    int a,b;
    cin>>a>>b;

    Rational A(a,b);

    cout<<"start"<<endl;

if((a==0  || b==0) || (a>b)){
    cout<<"Input non corretto";
}
else{

    bool chek=true;

    for(int i=2;chek==true;i++){
   // cout<<"TEST"<<endl;

    Rational B(1,i);
    if(Numbers::less(A,B)==false){ //  less:: if A<B  return true
        A=sub(A,B);
        cout<<B;
        if(A.numerator==0){}
        else
        cout<<" + ";


        if(A.numerator==0)
        chek=false;
    }



    }

}



    cout<<endl;
    cout << "end" << endl;

}