// nestedIfElseDemo3.cpp
//
// Displays the letter grade
// corresponding to a percentage score.
//
// Demonstrates nested if/else with indentation
// standard for a multiway branch, and with
// an else for every if in the nested if/else.
// Also uses return statement where standard.

#include <iostream>

using namespace std;

int main()
{
   // Announce purpose of program:
   cout << "This program determines the letter grade"
                  << " corresponding to a"
                  << " percentage score." << endl;

   // Ask user for percentage score:
   cout << "Enter percentage score:>";
   int score;
   cin >> score;

   // Check range of input:
   if ( score < 0 || score > 100 )
   {
      cout << "You entered " << score
                 << ", must be in range [0, 100]." << endl;
      return 1;
   }  // if

   // Determine the corresponding letter grade:
   char grade;

   if ( score >= 90 )
      grade = 'A';
   else if ( score >= 80 )
      grade = 'B';
   else if ( score >= 70 )
      grade = 'C';
   else if ( score >= 60 )
      grade = 'D';
   else   // if ( score < 60 )
      grade = 'F';

   // Output percentage score and letter grade:
   cout << "A score of " << score
               << " receives a grade of "
               << grade << "." << endl;

   return 0;
}  // function main