csvavg.cpp

#include <iostream>
#include <fstream>
#include <sstream>

using namespace std;

class StudentProcessor {
    string filename;
    ifstream file;

public:
    StudentProcessor(string fname) {
        filename = fname;
        file.open(filename);
        if (!file.is_open()) {
            cout << "Error opening file!" << endl;
        }
    }

    // User-defined stoi function
    int stringToInt(string s) {
        int num = 0;
        for (int i = 0; i < s.length(); i++) {
            if (s[i] >= '0' && s[i] <= '9') {
                num = num * 10 + (s[i] - '0');
            } else {
                // handle invalid character
                cout << "Invalid number string: " << s << endl;
                return 0;
            }
        }
        return num;
    }

    void processStudents() {
        string line;
        while (getline(file, line)) {
            stringstream ss(line);
            string name, score1, score2, score3;

            getline(ss, name, ',');
            getline(ss, score1, ',');
            getline(ss, score2, ',');
            getline(ss, score3, ',');

            int m1 = stringToInt(score1);
            int m2 = stringToInt(score2);
            int m3 = stringToInt(score3);

            float avg = (m1 + m2 + m3) / 3.0;

            if (avg >= 75) {
                cout << "Name: " << name << ", Average: " << avg << endl;
            }
        }
    }

    ~StudentProcessor() {
        file.close();
    }
};

int main() {
   // char* fname = new char[100];
   string fname;
    cout << "Enter the CSV filename: ";
  //  cin >> fname;
  fname="Marks.csv";

    StudentProcessor sp(fname);
    sp.processStudents();

   // delete[] fname;
    return 0;
}