Question

Write a program that randomly generates 100 dates and store them into a vector. Use the Date.h provided . The dates generated must be within 1000 days after 1/1/2000. and Sort the 100 dates generated in ascending order.

date.h

#ifndef DATE_H_
#define DATE_H_

#include
#include

using namespace std;

class Date {
   friend ostream &operator<<( ostream &, const Date & );
private:
   int day;
   int month;
   int year;
static const int days[]; // array of days per month
void helpIncrement(); // utility function for incrementing date

public:
   Date(int=1, int=1, int=0);
   void setDate(int,int,int);
   bool leapYear( int ) const; // is date in a leap year?
bool endOfMonth( int ) const; // is date at the end of month?
Date &operator++(); // prefix increment operator
Date operator++( int ); // postfix increment operator
const Date &operator+=( int ); // add days, modify object
bool operator<(const Date&) const;

   void showdate();
};

const int Date::days[] =
{ 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

Date::Date(int d, int m, int y) {
day = d;
month = m;
year = y;
// initialize static member at file scope; one classwide copy
}

// set month, day and year
void Date::setDate( int dd, int mm, int yy )
{
year = yy;
month = ( mm >= 1 && mm <= 12 )? mm : 1;

// test for a leap year
if ( month == 2 && leapYear( year ) )
day = ( dd >= 1 && dd <= 29 ) ? dd : 1;
else
day = ( dd >= 1 && dd <= days[ month ] ) ? dd : 1;
} // end function setDate

// if the year is a leap year, return true; otherwise, return false
bool Date::leapYear( int testYear ) const
{
if ( testYear % 400 == 0 ||
( testYear % 100 != 0 && testYear % 4 == 0 ) )
return true; // a leap year
else
return false; // not a leap year
} // end function leapYear

// determine whether the day is the last day of the month
bool Date::endOfMonth( int testDay ) const
{
if ( month == 2 && leapYear( year ) )
return testDay == 29; // last day of Feb. in leap year
else
return testDay == days[ month ];
} // end function endOfMonth

// function to help increment the date
void Date::helpIncrement()
{
// day is not end of month
if ( !endOfMonth( day ) )
day++; // increment day
else
if ( month < 12 ) // day is end of month and month < 12
{
month++; // increment month
day = 1; // first day of new month
} // end if
else // last day of year
{
year++; // increment year
month = 1; // first month of new year
day = 1; // first day of new month
} // end else
} // end function helpIncrement

// overloaded prefix increment operator
Date &Date::operator++()
{
helpIncrement(); // increment date
return *this; // reference return to create an lvalue
} // end function operator++

// overloaded postfix increment operator; note that the
// dummy integer parameter does not have a parameter name
Date Date::operator++( int )
{
Date temp = *this; // hold current state of object
helpIncrement();

// return unincremented, saved, temporary object
return temp; // value return; not a reference return
} // end function operator++

// add specified number of days to date
const Date &Date::operator+=( int additionalDays )
{
for ( int i = 0; i < additionalDays; i++ )
helpIncrement();

return *this; // enables cascading
} // end function operator+=

// overloaded output operator
ostream &operator<<( ostream &output, const Date &d )
{
// static string monthName[ 13 ] = { "", "January", "February",
// "March", "April", "May", "June", "July", "August",
// "September", "October", "November", "December" };
//
// output << d.day << " " << monthName[ d.month ] << " "<< d.year;
   output << setfill('0')
           << setw(2) << d.day << '/'
           << setw(2) << d.month << '/'
           << setw(4) << d.year;

   return output; // enables cascading
} // end function operator<<

bool Date::operator<(const Date& right) const {
   return (year < right.year || (year == right.year && month < right.month) ||
           (year == right.year && month == right.month && day < right.day));
}

void Date::showdate()
{
cout << "The date is ";
cout << setfill('0')
       << setw(2) << day << '/'
       << setw(2) << month << '/'
       << setw(2) << year % 100
       << endl;
return;
}

#endif /* DATE_H_ */

Answer 1

Here is the program:

#include <iostream>
#include "date.h"
#include <cstdlib>
#include <vector>
#include <algorithm>
using namespace std;

int main()
{
    
    vector<Date> dv;
    
    
    for (int i = 0; i < 100; i++) {
        // Random number less than 1000
        int daysAfter2K = (rand () ) % 1000;
        // Find date after 1/1/2000 that is daysAfter2K days later
        int yr = daysAfter2K / 365;
        int mn = (daysAfter2K - yr * 365) / 30 + 1;
        int dt = daysAfter2K - yr * 365 - (mn - 1) * 30;
        yr = yr + 2000;
        
        Date d;
        d.setDate (dt, mn, yr);
        dv.push_back (d);
    }

    sort (dv.begin(), dv.end());
    
    for (const auto &d : dv)
        cout<<d << endl;

    return 0;
}

Note that lines 3 and 4 in date.h are incomplete in code snippet given in problem, they should be:

#include <iostream>
#include <iomanip>