C++ Exercises: Check if a given number is circular prime or not

Last update on December 20 2024 12:30:51 (UTC/GMT +8 hours)

Write a C++ program to check if a given number is circular prime or not.

Sample Solution:

C++ Code :

#include<iostream>
#include<cmath>
using namespace std;

int flg; // Global variable to track whether a number is prime or not

// Function to check if a number is prime
void chkPrime(long int n)
{
    long int i = n - 1; // Initialize the variable i

    // Loop to check for factors of the number 'n'
    while (i >= 2)
    {
        if (n % i == 0) // If 'n' is divisible by 'i'
        {
            flg = 1; // Set flag to 1 indicating it's not a prime number
        }
        i--; // Decrement 'i'
    }
}

// Function to generate all combinations of a number and check if they are prime
void AllCombination(long int a)
{
    long int b1, c1, d1, e1, i, j, k, s1, z1, v1, x[8], y[8], m; // Declare variables

    b1 = a; // Store the number 'a' in 'b1'
    i = 0;

    // Loop to break the number into its digits and store in an array
    while (b1 > 0)
    {
        y[i] = b1 % 10; // Store the last digit of 'b1' in array 'y'
        b1 = b1 / 10; // Remove the last digit
        i++;
    }

    c1 = 0;

    // Reversing the digits to create the combinations
    for (j = i - 1; j >= 0; j--)
    {
        x[c1] = y[j]; // Store reversed digits in array 'x'
        c1++;
    }

    m = i;

    // Generating combinations and checking if they are prime
    while (m > 0)
    {
        c1 = m - 1;
        d1 = i - 1;
        e1 = 0;
        s1 = 0;

        while (e1 < i)
        {
            z1 = pow(10, d1); // Calculate power of 10
            v1 = z1 * x[c1 % i]; // Multiply power of 10 with digit
            c1++;
            d1--;
            e1++;
            s1 = s1 + v1; // Calculate the combined number
        }

        m--;
        chkPrime(s1); // Check if the combined number is prime
    }
}

int main()
{
    long int num1;
    cout << "\n\n Check whether a given number is circular prime or not: \n";
    cout << " -----------------------------------------------------------\n";
    cout << " Input a Number: ";
    cin >> num1; // Input a number

    flg = 0; // Initialize flag to 0
    AllCombination(num1); // Call function to generate combinations

    // Check if the number is circular prime or not based on the flag value
    if (flg == 0)
    {
        cout << " The given number is a circular prime Number." << endl;
    }
    else
    {
        cout << " The given number is not a circular prime Number." << endl;
    }
    return 0; // Return from main function
}

Sample Output:

Check whether a given number is circular prime or not:                
 -----------------------------------------------------------           
 Input a Number: 11                                                    
 The given number is a circular prime Number

Flowchart:

C++ Code Editor:

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