//-----------------------------------------------------------------------------
// Find the min and max of a list of students.
// Data includes last name, first name, ID, and grade.  For example:
//
// duck donald 5000 80
// mouse mickey 2200 75
// witch wicked 7800 92
//
// Assumptions:  
//    -- Format of data is correct.
//    -- All names are no more than MAXLENGTH.
//    -- IDs are correctly sized as integers.
//-----------------------------------------------------------------------------

#include <iostream> 
#include <iomanip>
#include <fstream> 
using namespace std;

int const MAXSIZE = 50;                   // maximum number of students
int const MAXLENGTH = 30;                 // maximum string length

struct Student {                          // information on one student
   int id;
   int grade;
   char lastName[MAXLENGTH];    
   char firstName[MAXLENGTH];   
   // more data as needed
};

// prototypes
bool readData(Student [], int& );            // read data for class of students
void printList(const Student [], int);       // print student list
bool lessThan(int, int);                     // is first < second?
bool greaterThan(int, int);                  // is first > second?
int findExtreme(const Student [], int, bool (*)(int,int));

//----------------------------------  main  -----------------------------------
int main() {
   Student myClass[MAXSIZE];                 // all the students
   int size = 0;                             // total number of students
 
   // get student data from a file, fill array then sort and print
   bool success = readData(myClass, size);
   if (success) {

      printList(myClass, size);             // print student list
      cout << endl;

      // find high and low grade
      int high = findExtreme(myClass, size, greaterThan);
      int low = findExtreme(myClass, size, lessThan);
      cout << "The high grade is " << high << endl;
      cout << "The low grade is " << low << endl;
   }
   return 0;
}

//-----------------------------------------------------------------------------
// readData
// read the data from a file for one class of students, place into array
//-----------------------------------------------------------------------------

bool readData(Student myClass[], int& size) {
   // create file object and open the datafile 
   ifstream infile("ptrToFunc.txt");
   if (!infile) {
      cerr << "File could not be opened." << endl;
      return false;
   }

   while (size < MAXSIZE && infile >> myClass[size].lastName
                                   >> myClass[size].firstName
                                   >> myClass[size].id       
                                   >> myClass[size].grade    ) 
      size++;

   return true;
}

//-----------------------------------------------------------------------------
// printList
// print the list of students
//-----------------------------------------------------------------------------

void printList(const Student myClass[], int size) {
   for (int i=0; i < size; i++)  
      cout << setw(4) << myClass[i].id 
           << setw(4) << myClass[i].grade 
           << "  " << myClass[i].lastName 
           << " " << myClass[i].firstName << endl;
}

//-----------------------------------------------------------------------------
// lessThan
// return true if parameter one is less than parameter two, false othewise
//-----------------------------------------------------------------------------
bool lessThan(int num1, int num2) {
   return num1 < num2;
}

//-----------------------------------------------------------------------------
// greaterThan
// return true if parameter one is greater than parameter two, false othewise
//-----------------------------------------------------------------------------
bool greaterThan(int num1, int num2) {
   return num1 > num2;
}

//-----------------------------------------------------------------------------
// findExtreme
// find the extreme value, determined by compare function, in an array of ints
//-----------------------------------------------------------------------------
int findExtreme(const Student myClass[], int size, bool (*compare)(int,int)) {
   int extreme = myClass[0].grade;
   for (int i=0; i < size; i++) {
      if ((*compare)(myClass[i].grade, extreme))
	 extreme = myClass[i].grade;
   }
   return extreme;
}