// Name:  Alan Helms
// Class: CPT 232 C++ I
// Times: MWF 9:00 - 9:50
// Semester: Spring 2-22-2003
// Project Name: Bdate_vfx.cpp
// Program Purpose: This program was designed to allow users to enter the
//                  current date: month, day, year, also allow user to enter
//                  the users birth date: month, day, year. Once the dates have
//                  been collected, the program will output the users age and
//                  then request if any more birth dates need to be entered.
//                  Bdate_vfx.cpp works for any number of birth dates. if user
//                  requests no more entries, then the program will output the
//                  average age and the oldest age of the group.
//                  
//
// ****NOTE: THIS VERSION WAS CREATED WITH BORLAND'S C++ v5.02 EDITIOR****
// ****NOTE: MODIFIED FOR MICORSOFT VISUAL STUDIO C++****


#include<iostream>
using std::cin;
using std::cout;
using std::endl;

#include<iomanip>
using std::setprecision;
using std::setiosflags;
using std::ios;

int main(){

   // int vars for current date.
	int cMonth=0, cDay=0, cYear=0;

   // int vars for user-entered dates.
   int uMonth=0, uDay=0, uYear=0;

   // int vars: counters, accumulators, ect.
	int oldest=0, counter=0, totalAges=0, nAge=0;

   // check figure for yes and no.
	char yes_NO;

      // prompt user to enter the current date.
		cout << "What is today's date?\n";

      // "current date" do-while stucture.

		do {

      	//prompts user to enter the current month.
      	cout << "    month (1-12)\r";
			cin >> cMonth;  // that value is stored here.
      // tests to see value entered is between the range (1-12).
      // before moving onto the next section of code.
      } while  (!(cMonth >= 1 && cMonth <=12));


		do {
         //prompts user to enter the current day.
         cout << "    day (1-31)\r";
			cin >> cDay;  // that value is stored here.
      // tests to see value entered is between the range (1-31).
      // before moving onto the next section of code.
      } while  (!(cDay >= 1 && cDay <=31));

		do {
      	//prompts user to enter the current year.
      	cout << "     year (1800-2003)\r";
			cin >> cYear;  // that value is stored here.
      // tests to see value entered is between the range (1-12).
      // before moving onto the next section of code.
      } while  (!(cYear >= 1800 && cYear <=2003));

      // end "current date" do-while structure.

      // "user entered dates" do-wile stucture.

		do {
          // prompts user to enter their Birth date.
          cout << "\nWhat is your birthday?\n";

          do {
          	 // propmts user to enter the month of there birth date.
             cout << "    month (1-12)\r";
             cin >> uMonth;  // that value is stored here.
          // test to see value entered is between the range (1-12).
          // before moving onto the next section of code.
          } while  (!(uMonth >= 1 && uMonth <=12));

          do {
          	 // propmts user to enter the day of there birth date.
             cout << "    day (1-31)\r";
             cin >> uDay;  // that value is stored here.
          // test to see value entered is between the range (1-12).
          // before moving onto the next section of code.
          } while  (!(uDay >= 1 && uDay <=31));

          do {
             // propmts user to enter the year of there birth date.
          	 cout << "      year (1800-2003)\r";
             cin >> uYear;  // that value is stored here.
          // test to see value entered is between the range (1-12).
          // before moving onto the next section of code.
          } while  (!(uYear >= 1800 && uYear < 2003));


          // substract the values of current year and user year and assign it
          // to the variable "nAge".
          nAge = cYear - uYear;

          // this section of code determines if the age needs to be decremented
          // by one year or not, also determines the oldest age and accumulates
          // the total number of ages entered. Outputs the result to
          // the screen.

          // user month >= current month.
          if ( uMonth >= cMonth ){
            //  TRUE: user day >= current day.
           	if ( uDay >= cDay ){
              // output age.
            	cout << "You are " << nAge << " years old." << endl;
               //TRUE: age > oldest.
               if ( nAge > oldest ){
                  //TRUE: age added to "totalages".
          			totalAges += nAge;
                  //oldest set to age.
          			oldest = nAge;
               }
               else{
                  //ELSE: age added to "totalages".
          			totalAges += nAge;
               }

            }
            else{
            	// user month not >= current month.
               //age = age - 1
            	nAge -= 1;
               // output age.
               cout << "You are " << nAge << " years old." << endl;
               //TRUE: age > oldest.
               if ( nAge > oldest ){
                  //TRUE: age added to "totalages".
          			totalAges += nAge;
                  //oldest set to age.
          			oldest = nAge;
          		}
          		else{
                  //ELSE: age added to "totalages".
          			totalAges += nAge;
          		}
            }
          }
          else{
          	nAge -= 1;
            // output age.
          	cout << "You are " << nAge << " years old." << endl;
            //TRUE: age > oldest.
            if ( nAge > oldest ){
            	//TRUE: age added to "totalages".
          		totalAges += nAge;
               //oldest set to age.
          		oldest = nAge;
          	}
         	else{
               //ELSE: age added to "totalages".
          		totalAges += nAge;
          	}

          }

          // prompt user to enter more dates if needed.
          cout << "Are there any more folks who'd like to enter their ";
          cout << "birth dates?\n(Enter y for yes, n for no)\n";
          cin >> yes_NO; // hold char value  n||N.
          ++counter; // increments the counter by one.

      // test to see if var "yes_NO" is a 'y' or 'n' before moving on to
      // next section of code.
      // if var "yes_NO" is equal to 'n' or 'N' then
      // the loop is terminated, otherwise loop until condition is met.
      } while ( yes_NO != 'n' && yes_NO != 'N' );

      // end "user entered dates" do-wile stucture.
      
      // output the average age.
      cout << "\nAverage age is = "
           // set the visiable decimal point to 1 to the right of the decimal.
           << setprecision(1)
           // set flags not to convert output to scientific nototation.
           // set flags to show the decimal point.
           << setiosflags(ios::fixed | ios::showpoint)
           // type casting of double to int totalAges to perform real division.
           // cast double totalAges divied by the counter gives average age
           // of group.
           << (double) totalAges / counter << endl;

      // output the oldest person of the group
      cout << "The elder statesperson of your group is ";
      cout << oldest << " years old." << endl;

	return 0;

} // end program