Answer:
Here's an example program in C++ that accepts an unknown number of grades and calculates the GPA and letter grade for each grade entered:
#include <iostream>
#include <vector>
#include <iomanip>
using namespace std;
int main() {
int num_grades;
vector<int> grades;
double total_points = 0;
double gpa;
char letter_grade;
// Get number of grades
cout << "Enter number of grades: ";
cin >> num_grades;
// Get grades
cout << "Enter grades (0-4): ";
for (int i = 0; i < num_grades; i++) {
int grade;
cin >> grade;
if (grade >= 0 && grade <= 4) {
grades.push_back(grade);
total_points += grade;
}
else {
grades.push_back(0);
}
}
// Calculate GPA
if (num_grades > 0) {
gpa = total_points / num_grades;
}
else {
gpa = 0;
}
// Output grades and GPA
cout << fixed << setprecision(2);
cout << "Grades and GPA:\\";
for (int i = 0; i < num_grades; i++) {
int grade = grades[i];
if (grade == 4) {
letter_grade = 'A';
}
else if (grade == 3) {
letter_grade = 'B';
}
else if (grade == 2) {
letter_grade = 'C';
}
else if (grade == 1) {
letter_grade = 'D';
}
else {
letter_grade = 'F';
}
cout << "Grade " << i+1 << ": " << letter_grade << "\\";
}
cout << "GPA: " << gpa << "\\";
return 0;
}
Step-by-step explanation:
The program first prompts the user for the number of grades, then loops through that many times to get each grade from the user. If the grade entered is between 0 and 4, it is added to the grades vector and its value is added to total_points. Otherwise, a 0 is added to the grades vector instead.
After all grades have been entered, the program calculates the GPA by dividing total_points by the number of grades entered (making sure to check that num_grades is greater than 0 to avoid a divide-by-zero error).
Finally, the program loops through each grade in the grades vector, converts it to a letter grade, and outputs both the letter grade and the GPA. Note that fixed and setprecision(2) are used to format the GPA to two decimal places.
Here's a pseudocode version of the program:
Prompt the user to enter the number of grades to be entered
Read in the number of grades to be entered
Initialize a variable to hold the sum of the grades
Initialize a variable to hold the count of valid grades
Initialize an empty array to hold the entered grades
Loop through the number of grades entered:
a. Read in the next grade
b. If the grade is between 0 and 4, add it to the sum of the grades and increment the count of valid grades
c. If the grade is not between 0 and 4, set it to 0
d. Add the grade to the array of entered grades
Calculate the GPA by dividing the sum of the grades by the count of valid grades
Output the calculated GPA
Loop through the array of entered grades:
a. Calculate the letter grade for each grade based on the grading scale provided in the prompt
b. Output the letter grade for each grade
Note: It's important to validate the input grades to ensure they fall within the accepted range of 0-4. This is why step 6c is included, and why any invalid grades are set to 0. Additionally, some schools or institutions may use different grading scales, so it's important to verify that the provided grading scale matches the one being used before implementing this program in a real-world scenario.