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

int main()
{
    // declaration of type
    const int numberOfTests = 4;
    const int numberOfStudents = 5;
    string namesOfStudents[numberOfStudents];
    double studenta[numberOfTests];
    double studentb[numberOfTests];
    double studentc[numberOfTests];
    double studentd[numberOfTests];
    double studente[numberOfTests];
    int count;
    double y = 0;
    string lettergrade;


   // what to input and which
   cout << "enter the names of the 5 students ." << std::endl;
 for(count = 0; count < numberOfStudents; count++)
    {
    cout << "student name  " << count+1 << " of " << numberOfStudents << ". ";
    cin >> namesOfStudents[count];
    }

   cout << "enter the numeric scores for " << namesOfStudents[0] << "'s" << " tests." << std::endl;
 for(count = 0; count < numberOfTests; count++)
    {
    cout << "test number  " << count+1 << " of " << numberOfTests << ". ";
    cin >> studenta[count];
     if(studenta[count] > 100 || studenta[count] < 0)
        {
            cout << "invalid score" << endl;
            count--;
        }
    }

   cout << "enter the numeric scores for " << namesOfStudents[1] << "'s" << " tests." << std::endl;
 for(count = 0; count < numberOfTests; count++)
    {
    cout << "test number  " << count+1 << " of " << numberOfTests << ". ";
    cin >> studentb[count];
     if(studentb[count] > 100 || studentb[count] < 0)
        {
             cout << "invalid score" << endl;
            count--;
        }
    }

   cout << "enter the numeric scores for " << namesOfStudents[2] << "'s" << " tests." << std::endl;
 for(count = 0; count < numberOfTests; count++)
    {
    cout << "test number  " << count+1 << " of " << numberOfTests << ". ";
    cin >> studentc[count];
     if(studentc[count] > 100 || studentc[count] < 0)
        {
             cout << "invalid score" << endl;
            count--;
        }
    }

   cout << "enter the numeric scores for " << namesOfStudents[3] << "'s" << " tests." << std::endl;
 for(count = 0; count < numberOfTests; count++)
    {
    cout << "test number  " << count+1 << " of " << numberOfTests << ". ";
    cin >> studentd[count];
     if(studentd[count] > 100 || studentd[count] < 0)
        {
             cout << "invalid score" << endl;
            count--;
        }
    }

   cout << "enter the numeric scores for " << namesOfStudents[4] << "'s" << " tests." << std::endl;
 for(count = 0; count < numberOfTests; count++)
    {
    cout << "test number  " << count+1 << " of " << numberOfTests << ". ";
    cin >> studente[count];
     if(studente[count] > 100 || studente[count] < 0)
        {
             cout << "invalid score" << endl;
            count--;
        }
    }


for (count = 0; count < numberOfTests; count++)
    {
        y = y + studenta[count];
    }
y = y / 4;
if( y = 90)
    {
        lettergrade = "A";
    }
else if ( y >= 80 && y <= 89)
    {
        lettergrade = "B";
    }
else if ( y >= 70 && y <= 79)
    {
        lettergrade = "C";
    }
else if ( y >= 60 && y <= 69)
    {
        lettergrade = "D";
    }
else if ( y >= 0 && y <= 59)
    {
        lettergrade = "F";
    }


cout << "the student: " << namesOfStudents[0] << " Average Score is: " <<  y << " with a letter grade of " << lettergrade << "." << endl;

for (count = 0; count < numberOfTests; count++)
    {
        y = y + studentb[count];
    }
y = y / 4;
if( y = 90)
    {
        lettergrade = "A";
    }
else if ( y >= 80 && y <= 89)
    {
        lettergrade = "B";
    }
else if ( y >= 70 && y <= 79)
    {
        lettergrade = "C";
    }
else if ( y >= 60 && y <= 69)
    {
        lettergrade = "D";
    }
else if ( y >= 0 && y <= 59)
    {
        lettergrade = "F";
    }



cout << "the student: " << namesOfStudents[1] << " Average Score is: " <<  y << " with a letter grade of " << lettergrade << "." << endl;

for (count = 0; count < numberOfTests; count++)
    {
        y = y + studentc[count];
    }
y = y / 4;
if( y = 90)
    {
        lettergrade = "A";
    }
else if ( y >= 80 && y <= 89)
    {
        lettergrade = "B";
    }
else if ( y >= 70 && y <= 79)
    {
        lettergrade = "C";
    }
else if ( y >= 60 && y <= 69)
    {
        lettergrade = "D";
    }
else if ( y >= 0 && y <= 59)
    {
        lettergrade = "F";
    }



cout << "the student: " << namesOfStudents[2] << " Average Score is: " <<  y << " with a letter grade of " << lettergrade << "." << endl;

for (count = 0; count < numberOfTests; count++)
    {
        y = y + studentd[count];
    }
y = y / 4;
if( y = 90)
    {
        lettergrade = "A";
    }
else if ( y >= 80 && y <= 89)
    {
        lettergrade = "B";
    }
else if ( y >= 70 && y <= 79)
    {
        lettergrade = "C";
    }
else if ( y >= 60 && y <= 69)
    {
        lettergrade = "D";
    }
else if ( y >= 0 && y <= 59)
    {
        lettergrade = "F";
    }



cout << "the student: " << namesOfStudents[3] << " Average Score is: " <<  y << " with a letter grade of " << lettergrade << "." << endl;

for (count = 0; count < numberOfTests; count++)
    {
        y = y + studente[count];
    }
y = y / 4;
if( y = 90)
    {
        lettergrade = "A";
    }
else if ( y >= 80 && y <= 89)
    {
        lettergrade = "B";
    }
else if ( y >= 70 && y <= 79)
    {
        lettergrade = "C";
    }
else if ( y >= 60 && y <= 69)
    {
        lettergrade = "D";
    }
else if ( y >= 0 && y <= 59)
    {
        lettergrade = "F";
    }

cout << "the student: " << namesOfStudents[4] << " Average Score is: " <<  y << " with a letter grade of " << lettergrade << "." << endl;
return 0;

}