SGS lab 1

#include <iostream>

using namespace std;

int main()
{
    while (true)
    {
        int num;
        cout << "Enter 1 for Hello World :  \nEnter 2 for Calculation : \nEnter 3 for Swapping of 2 numbers : \nEnter 4 for Swapping of 3 numbers : \nEnter 5 for Fibonacci series : \nEnter 6 for Square of number : \nEnter 7 for Area of triangle : \nEnter 8 for Area of circle : \nEnter 9 for Simple interest : \nEnter 10 for checking Leap year or not : \nEnter 11 for Check character vowel or not : \nEnter 12 for Table of any number :- \nEnter 13 for Prime number :- \n\nEnter any number from above stated = ";
        cin >> num;

        switch (num)
        {
            case 1:
                cout << "Hello World";
                break;
            case 2:
            {
                int a1, a2, val;
                cout << "Enter any two numbers = ";
                cin >> a1 >> a2;
                cout << "Enter 1 for Addition :- \nEnter 2 for Subtraction :- \nEnter 3 for Multiplication :- \nEnter 4 for Division :- \nEnter 5 for Modulus (Remainder) :- \nEnter 6 for All Calculation :- \n\nPlease Enter = ";
                cin >> val;

                switch (val)
                {
                case 1:
                    cout << "\nAddition = " << a1 + a2;
                    break;
                case 2:
                    cout << "\nSubtraction = " << a1 - a2;
                    break;
                case 3:
                    cout << "\nMultiplication = " << a1 * a2;
                    break;
                case 4:
                    if (a2 != 0)
                        cout << "\nDivision = " << a1 / a2;
                    else
                        cout << "\nDivision by zero is not allowed";
                    break;
                case 5:
                    if (a2 != 0)
                        cout << "\nModulus (Remainder) = " << a1 % a2;
                    else
                        cout << "\nModulus (Remainder) by zero is not allowed";
                    break;
                case 6:
                    cout << "\nAddition = " << a1 + a2;
                    cout << "\nSubtraction = " << a1 - a2;
                    cout << "\nMultiplication = " << a1 * a2;
                    if (a2 != 0)
                        cout << "\nDivision = " << a1 / a2;
                    else
                        cout << "\nDivision by zero is not allowed";
                    if (a2 != 0)
                        cout << "\nModulus (Remainder) = " << a1 % a2;
                    else
                        cout << "\nModulus (Remainder) by zero is not allowed";
                    break;
                default:
                    cout << "Invalid number";
                    break;
                }
            }
            break;
            case 3:
            {
                int b1, b2, choice;
                cout << "\nEnter 1 for Swapping with a third variable :- \nEnter 2 for Swapping without a third variable :- \n\nNow Enter here= ";
                cin >> choice;
                int b3;
                switch (choice)
                {
                case 1:
                    cout << "Enter the value of a and b = ";
                    cin >> b1 >> b2;
                    b3 = b1;
                    b1 = b2;
                    b2 = b3;
                    cout << "a=" << b1 << "\nb=" << b2;
                    break;
                case 2:
                    cout << "Enter the value of a and b = ";
                    cin >> b1 >> b2;
                    b1 = b1 + b2;
                    b2 = b1 - b2;
                    b1 = b1 - b2;
                    cout << "a=" << b1 << "\nb=" << b2;
                    break;
                default:
                    cout << "Invalid choice";
                    break;
                }
            }
            break;
            case 4:
            {
                int n1, n2, n3;
                cout << "Enter the value of a, b, and c = ";
                cin >> n1 >> n2 >> n3;
                int n4 = n1;
                n1 = n2;
                n2 = n3;
                n3 = n4;
                cout << "a=" << n1 << "\nb=" << n2 << "\nc=" << n3;
            }
            break;
            case 5:
            {
                int d1 = 0, d2 = 1, d3, d4, d5;
                cout << "Enter the number of values to be printed for the Fibonacci series = ";
                cin >> d5;
                cout << "Fibonacci Series :-" << endl;
                cout << d1 << endl
                     << d2;
                for (d4 = 3; d4 <= d5; d4++)
                {
                    d3 = d1 + d2;
                    d1 = d2;
                    d2 = d3;
                    cout << endl << d3;
                }
            }
            break;
            case 6:
            {
                int e;
                cout << "Enter any number you want the square of = ";
                cin >> e;
                cout << "Square of " << e << " = " << e * e;
            }
            break;
            case 7:
            {
                float base, height, area1;
                cout << "Enter the value of base and height = ";
                cin >> base >> height;
                area1 = (base * height) / 2;
                cout << "Area of Triangle = " << area1;
            }
            break;
            case 8:
            {
                float area, radius;
                cout << "Enter the value of the radius = ";
                cin >> radius;
                area = (22 * radius * radius) / 7;
                cout << "Area of Circle = " << area;
            }
            break;
            case 9:
            {
                float p, r, t, si;
                cout << "Enter the value of P, R, and T = ";
                cin >> p >> r >> t;
                si = (p * r * t) / 100;
                cout << "Simple Interest = " << si;
            }
            break;
            case 10:
            {
                int year;
                cout << "Enter any Year = ";
                cin >> year;
                if ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0))
                    cout << year << " is a Leap Year";
                else
                    cout << year << " is not a Leap Year";
            }
            break;
            case 11:
            {
                char ch;
                cout << "Enter any character = ";
                cin >> ch;
                switch (ch)
                {
                case 'a':
                case 'e':
                case 'i':
                case 'o':
                case 'u':
                case 'A':
                case 'E':
                case 'I':
                case 'O':
                case 'U':
                    cout << " " << ch << " is a Vowel";
                    break;
                default:
                    cout << " " << ch << " is not a Vowel";
                    break;
                }
            }
            break;
            case 12:
            {
                int n;
                cout << "Enter any number you want the table of = ";
                cin >> n;
                for (int i = 1; i <= 10; i++)
                {
                    cout << n << "*" << i << "=" << n * i << endl;
                }
            }
            break;
            case 13:
            {
                int n;
                cout << "Enter any number = ";
                cin >> n;
                if(n<=1){
                    cout<<"Not prime \n";
                    break;
                }
                bool check = true;
                for(int i=2 ; i<= (n/2) ; i++){
                    if(n%i==0){
                        check = false;
                        break;
                    }

                }
                if(check){
                    cout<<n<<" is prime\n";
                }
                else{
                    cout<<n<<" is not prime\n";
                }
            }
            break;
            default:
                cout << "Please enter a valid number";
                break;
        }

        cout << "\nDo you want to continue? (y/n): ";
        char choice;
        cin >> choice;
        if (choice != 'y' && choice != 'Y')
            break;
    }

    return 0;
}