Expert: Zlatko - 5/11/2010

Question
Hi Zlatko,
Thanks for your answer.I changed program .

Regards
Tina


#include <iostream>
#include <iomanip>
#include <sstream>
#include <string>
using namespace std;

string correctdate(void);
bool leapyear(int year);
int daysInMonth(int month, int year );
int dayFrom1900(int year, int month, int days);
int days(const string &date1, const string &date2);
int main()
{
    cout<<endl;
   string d1,date1,d2,date2;
   d1 = correctdate();
    
      cout<<endl<<endl;
      cout<<"\tPlease write the second date."<<endl;
      d2 = correctdate();
  
           cout<<endl;
         cout<<"total days are :"<<days(d1,d2)<<endl;

return 0;
}
‘’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’
int days(const string &date1 ,const string &date2)
{
int year1,year2,month1,month2,day1,day2;
int days1=0,days2=0;

istringstream iss(date1);
iss>>year1>>month1>>day1;
days1 = dayFrom1900(year1, month1, days1);

cout<<endl<<endl;
istringstream iss2(date2);
iss2>>year2>>month2>>day2;
days2 = dayFrom1900(year2, month2, days2);

int total_days = days2 - days1;
return total_days;
}

//------------------------------------------
//name:correctdate
//------------------------------------------
string correctdate(void)
{
int year, month,day;
string date;
bool dateok ;
 do
 {
dateok = true;
cout<<"\t**********DATE**********\n";
cout<<"\t write a date (yyyy mm dd): ";
getline(cin,date);


  istringstream iss(date);
   iss>>year>>month>>day;

  if (year<1900 || year>3000)
  {dateok = false;}

  if (month<1 || month>12)
  {dateok = false;}

  if(day <1 || day >31)
  {dateok = false;}

cout<<endl;
cout<<"\tYear = "<<year<<endl;
cout<<"\tMonth = "<<month<<endl;
cout<<"\tDay = "<<day<< " is a ";

  if (dateok)
  {cout<<"date is okey ."<<endl;}
  else
  {cout<<" date is not okey.try again !!!"<<endl<<endl;}

 }while(!dateok);
return date;
}
‘’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’
bool leapyear(int year)
{
  if (year % 400 == 0)
      return true;
      
  else if (year % 100 != 0)
      return false ;
     
  else (year % 4 == 0);
      return false ;

 }
‘’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’
int daysInMonth(int month, int year )
{
int day = 0;
if (month==1 || month==3 || month==5 || month==7 || month==8 || month==10 ||month==12)
 {   day = 31;
    return day ;  

 }
else if (month==4 || month==6 || month==9 || month==11)
 {   
    day = 30;
    return day ;  
 }

else
 {
    if (leapyear(year))
    {day = 29;
    return day ;  
    }
    
    else
    {
       day = 28;
       return day;
    }
  }
}
‘’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’’
int dayFrom1900(int year, int month, int days)
{
  int ar = 1900;
  int monad = month;
  int dag = 0;
do                  
{
   if(leapyear(ar))
   {dag += 366;}
    else
   {dag += 365;}

ar += 1;
}while(ar<year);
 
    if (ar == year)
   {
      do{
      dag = dag + daysInMonth(monad, ar);
      monad -= 1;
        }while(monad ==0);
   }
   if ( monad == 0 )
   {
   days = dag + days;
   }
return days;
}

Answer
Hello Tina.

I had a quick look at the program. I found only 1 serious problem.
Try 1999 1 1, and 2000 1 1, you get back 0 days.

The problem was in dayFrom1900. The monad loop was while(monad == 0). It should be while (monad > 0) or while (monad != 0). I prefer the first.

I fixed the program. My comments start with //ZM

Generally you did a good job.

Best regards
Zlatko

#include <iostream>
#include <iomanip>
#include <sstream>
#include <string>
using namespace std;

string correctdate(void);
bool leapyear(int year);
int daysInMonth(int month, int year );
int dayFrom1900(int year, int month, int days);
int days(const string &date1, const string &date2);

int main()
{
   cout<<endl;
   string d1,date1,d2,date2;
   d1 = correctdate();

   cout<<endl<<endl;
   cout<<"\tPlease write the second date."<<endl;
   d2 = correctdate();

   cout<<endl;
   cout<<"total days are :"<<days(d1,d2)<<endl;

   return 0;
}

int days(const string &date1 ,const string &date2)
{
   int year1,year2,month1,month2,day1,day2;
   int days1=0,days2=0;

   istringstream iss(date1);
   iss>>year1>>month1>>day1;
   days1 = dayFrom1900(year1, month1, days1);

   cout<<endl<<endl;
   istringstream iss2(date2);
   iss2>>year2>>month2>>day2;
   days2 = dayFrom1900(year2, month2, days2);

   int total_days = days2 - days1;
   return total_days;
}

//------------------------------------------
//name:correctdate
//------------------------------------------
string correctdate(void)
{
   int year, month,day;
   string date;
   bool dateok ;
   do
   {
       dateok = true;
       cout<<"\t**********DATE**********\n";
       cout<<"\t write a date (yyyy mm dd): ";
       getline(cin,date);


       istringstream iss(date);
       iss>>year>>month>>day;

       if (year<1900 || year>3000)
       {dateok = false;}

       if (month<1 || month>12)
       {dateok = false;}

       if(day <1 || day >31)
       {dateok = false;}

       cout<<endl;
       cout<<"\tYear = "<<year<<endl;
       cout<<"\tMonth = "<<month<<endl;
       cout<<"\tDay = "<<day<< " is a ";

       if (dateok)
       {cout<<"date is okey ."<<endl;}
       else
       {cout<<" date is not okey.try again !!!"<<endl<<endl;}

   }while(!dateok);
   return date;
}

bool leapyear(int year)
{
   if (year % 400 == 0)
       return true;

   else if (year % 100 != 0)
       return false ;

   //ZM This semicolon at the end of the line below means that the else has no consequent. You should remove the entire line
   else (year % 4 == 0);
   return false ;

}

int daysInMonth(int month, int year )
{
   int day = 0;
   if (month==1 || month==3 || month==5 || month==7 || month==8 || month==10 ||month==12)
   {   day = 31;
   return day ;  

   }
   else if (month==4 || month==6 || month==9 || month==11)
   {   
       day = 30;
       return day ;  
   }

   else
   {
       if (leapyear(year))
       {day = 29;
       return day ;  
       }

       else
       {
           day = 28;
           return day;
       }
   }

   //ZM should have a return as the last line. I know that the logic above forces a return in all cases.
   return day;
}

int dayFrom1900(int year, int month, int days)
{
   int ar = 1900;
   int monad = month;
   int dag = 0;
   do                  
   {
       if(leapyear(ar))
       {dag += 366;}
       else
       {dag += 365;}

       ar += 1;
   }while(ar<year);

   if (ar == year)
   {
       do{
           dag = dag + daysInMonth(monad, ar);
           monad -= 1;
       }while(monad > 0); //ZM Correction, was monad==0
   }
   if ( monad == 0 )
   {
       days = dag + days;
   }
   return days;
}