DSA_F23.cpp

//                    ---- DSA PRACTICAL ----
// Department maintains a student information. The file contains roll number, 
// name, division and address. Allow user to add, delete information of student. 
// Display information of particular employee. If record of student does not exist 
// an appropriate message is displayed. If it is, then the system displays the student 
// details. Use sequential file to main the data.  

#include <iostream>
#include <fstream>
#include <cstring>
using namespace std;
class tel
{

public:
    int rollNo, roll1;
    char name[10];
    char div;
    char address[20];
    void accept()
    {
        cout << "\n\tEnter Roll Number : ";
        cin >> rollNo;
        cout << "\n\tEnter the Name : ";
        cin >> name;
        cout << "\n\tEnter the Division:";
        cin >> div;
        cout << "\n\tEnter the Address:";
        cin >> address;
    }
    void accept2()
    {
        cout << "\n\tEnter the Roll No. to modify : ";
        cin >> rollNo;
    }
    void accept3()
    {
        cout << "\n\tEnter the name to modify : ";
        cin >> name;
    }
    int getRollNo()
    {
        return rollNo;
    }
    void show()
    {

        cout << "\n\t" << rollNo << "\t\t" << name << "\t\t" << div << "\t\t" << address;
    }
};
int main()
{
    int i, n, ch, ch1, rec, start, count, add, n1, add2, start2, n2, y, a, b, on, oname, add3, start3, n3, y1, add4, start4, n4;
    char name[20], name2[20];
    tel t1;
    count = 0;
    fstream g, f;
    do
    {
        cout << "\n>>>>>>>>>>>>>>>>>>>>>>MENU<<<<<<<<<<<<<<<<<<<<";
        cout << "\n1.Insert and overwrite\n2.Show\n3.Search & Edit(number)\n4.Search & Edit(name)\n5.Search & Edit(onlynumber)\n6.Search & edit(only name)\n 7.Delete a Student Record\n 8.Exit\n\tEnter the Choice\t:";
        cin >> ch;
        switch (ch)
        {
        case 1:
            f.open("StuRecord.txt", ios::out);
        x:
            t1.accept();
            f.write((char *)&t1, (sizeof(t1)));
            cout << "\nDo you want to enter more records?\n1.Yes\n2.No";
            cin >> ch1;
            if (ch1 == 1)
                goto x;
            else
            {
                f.close();
                break;
            }

        case 2:
            f.open("StuRecord.txt", ios::in);
            f.read((char *)&t1, (sizeof(t1)));
            // cout<<"\n\tRoll No.\t\tName \t\t Division \t\t Address";
            while (f)
            {
                t1.show();
                f.read((char *)&t1, (sizeof(t1)));
            }
            f.close();
            break;
        case 3:
            cout << "\nEnter the roll number you want to find";
            cin >> rec;
            f.open("StuRecord.txt", ios::in | ios::out);
            f.read((char *)&t1, (sizeof(t1)));
            while (f)
            {
                if (rec == t1.rollNo)
                {
                    cout << "\nRecord found";
                    add = f.tellg();
                    f.seekg(0, ios::beg);
                    start = f.tellg();
                    n1 = (add - start) / (sizeof(t1));
                    f.seekp((n1 - 1) * sizeof(t1), ios::beg);
                    t1.accept();
                    f.write((char *)&t1, (sizeof(t1)));
                    f.close();
                    count++;
                    break;
                }
                f.read((char *)&t1, (sizeof(t1)));
            }
            if (count == 0)
                cout << "\nRecord not found";
            f.close();
            break;

        case 4:
            cout << "\nEnter the name you want to find and edit";
            cin >> name;
            f.open("StuRecord.txt", ios::in | ios::out);
            f.read((char *)&t1, (sizeof(t1)));
            while (f)
            {
                y = (strcmp(name, t1.name));
                if (y == 0)
                {
                    cout << "\nName found";
                    add2 = f.tellg();
                    f.seekg(0, ios::beg);
                    start2 = f.tellg();
                    n2 = (add2 - start2) / (sizeof(t1));
                    f.seekp((n2 - 1) * sizeof(t1), ios::beg);
                    t1.accept();
                    f.write((char *)&t1, (sizeof(t1)));
                    f.close();
                    break;
                }
                f.read((char *)&t1, (sizeof(t1)));
            }
            break;
        case 5:
            cout << "\n\tEnter the roll number you want to modify";
            cin >> on;
            f.open("StuRecord.txt", ios::in | ios::out);
            f.read((char *)&t1, (sizeof(t1)));
            while (f)
            {
                if (on == t1.rollNo)
                {
                    cout << "\n\tNumber found";
                    add3 = f.tellg();
                    f.seekg(0, ios::beg);
                    start3 = f.tellg();
                    n3 = (add3 - start3) / (sizeof(t1));
                    f.seekp((n3 - 1) * (sizeof(t1)), ios::beg);
                    t1.accept2();
                    f.write((char *)&t1, (sizeof(t1)));
                    f.close();
                    break;
                }
                f.read((char *)&t1, (sizeof(t1)));
            }
            break;
        case 6:
            cout << "\nEnter the name you want to find and edit";
            cin >> name2;
            f.open("StuRecord.txt", ios::in | ios::out);
            f.read((char *)&t1, (sizeof(t1)));
            while (f)
            {
                y1 = (strcmp(name2, t1.name));
                if (y1 == 0)
                {
                    cout << "\nName found";
                    add4 = f.tellg();
                    f.seekg(0, ios::beg);
                    start4 = f.tellg();
                    n4 = (add4 - start4) / (sizeof(t1));
                    f.seekp((n4 - 1) * sizeof(t1), ios::beg);
                    t1.accept3();
                    f.write((char *)&t1, (sizeof(t1)));
                    f.close();
                    break;
                }
                f.read((char *)&t1, (sizeof(t1)));
            }
            break;
        case 7:
            int roll;
            cout << "Please Enter the Roll No. of Student Whose Info You Want to Delete: ";
            cin >> roll;
            f.open("StuRecord.txt", ios::in);
            g.open("temp.txt", ios::out);
            f.read((char *)&t1, sizeof(t1));
            while (!f.eof())
            {
                if (t1.getRollNo() != roll)
                    g.write((char *)&t1, sizeof(t1));
                f.read((char *)&t1, sizeof(t1));
            }
            cout << "The record with the roll no. " << roll << " has been deleted " << endl;
            f.close();
            g.close();
            remove("StuRecord.txt");
            rename("temp.txt", "StuRecord.txt");
            break;
        case 8:
            cout << "\n\tThank you";
            break;
        }
    } while (ch != 8);
}