C++ Code Examples: Basic Operations

Posted on Feb 7, 2025 in Spanish

C++ Code Examples

Generating Random Numbers

#include <iostream>
#include <cstdlib>
#include <ctime>

using namespace std;

int main()
{
    int num, c, aleatorio;
    srand(time(NULL));
    for (c = 1; c <= 10; c++)
    {
        aleatorio = rand() % (11 - 1);
        num = 1 + aleatorio;
        //num = 1 + rand()%(11-1); // Alternative
        cout << num << " ";
    }
    cin.get();
}

Calculating Area and Perimeter of a Circle

#include <iostream>

using namespace std;

int main()
{
    int radio;
    float area, perimetro;

    cout << "Introduce the radius of the circle: ";
    cin >> radio;

    area = 3.14 * radio * radio;
    perimetro = 3.14 * radio * 2;

    cout << "The area is: " << area << " and the perimeter is: " << perimetro;
    cin.get();
    cin.get();

    return 0;
}

Capturing and Displaying User Input

#include <iostream>
#include <conio.h>

using namespace std;

void hola(char nombre[50])
{
    cout << "Hello " << nombre;
}

int desplegar_edad(int edad)
{
    cout << "Your age is: " << edad;
    return 0;
}

int main()
{
    char nombre[50];
    int edad;
    cout << "What is your name? ";
    cin.getline(nombre, 50);
    cout << "What is your age? ";
    cin >> edad;
    hola(nombre);
    desplegar_edad(edad);
    getch();
}

Displaying Prime Numbers (While Loop)

#include <iostream>
#include <conio.h>

using namespace std;

int main()
{
    int cnt, i = 0, ii, res, nc = 0, np = 0;
    cout << "Enter the number of prime numbers you want to display: ";
    cin >> cnt;

    while (np != cnt)
    {
        i++;
        for (ii = 1; ii <= i; ii++)
        {
            res = i % ii;
            if (res == 0)
                nc = nc + 1;
        }

        if (nc == 2)
        {
            cout << i << " ";
            np++;
        }
        nc = 0;
    }
    getch();
}

Checking for Prime Numbers

#include <iostream>

using namespace std;

int main()
{
    int num, c, res, nc = 0;
    cout << "Enter a number: ";
    cin >> num;

    for (c = 1; c <= num; c++)
    {
        res = num % c;
        if (res == 0)
            nc++;
        //if (nc>2)  // Optimization: Could break if nc > 2
        // break;
    }

    if (nc == 2)
        cout << "It is prime";
    else
        cout << "It is not prime";
    cin.get();
    cin.get();
}

Sum of Two Values

#include <iostream>
#include <conio.h>

using namespace std;

int sumar(int num1, int num2)
{
    int r;
    r = num1 + num2;
    return r;
}

int main()
{
    int num1, num2, r;
    cout << "Enter the first value for the sum: ";
    cin >> num1;
    cout << "Enter the second value for the sum: ";
    cin >> num2;
    r = sumar(num1, num2);
    cout << "The total sum is: " << r;
    getch();
}

Incrementing Values by 2

#include <iostream>
#include <conio.h>


using namespace std;

int manejo_error(int a, int &r) // Use reference for 'r'
{
    if (a < 50)
    {
        cout << "You entered an invalid value";
        r = 1;
        return r;
    }
    else
    {
        r = 0;
        return r;
    }
}

int main()
{
    int a, i, r;
    cout << "Enter a value between 50 and 100: ";
    cin >> a;
    manejo_error(a, r);

    if (r == 0) // Corrected comparison
    {
        cout << "The values that increase by 2, from 50 up to 100, are: ";
        while (a <= 98) // a should be less or equal to 98
        {
            a = a + 2;
            cout << a << " ";

        }
    }
    getch();
}