Circular prime.java

// Program to check if a number is circular

// prime or not.

#include <iostream>

#include <cmath>

using namespace std;

 

// Function to check if a number is prime or not.

bool isPrime(int n)

{

    // Corner cases

    if (n <= 1)

        return false;

    if (n <= 3)

        return true;

 

    // This is checked so that we can skip

    // middle five numbers in below loop

    if (n % 2 == 0 || n % 3 == 0)

        return false;

 

    for (int i = 5; i * i <= n; i = i + 6)

        if (n % i == 0 || n % (i + 2) == 0)

            return false;

 

    return true;

}

 

// Function to check if the number is circular

// prime or not.

bool checkCircular(int N)

{

    // Count digits.

    int count = 0, temp = N;

    while (temp) {

        count++;

        temp /= 10;

    }

 

    int num = N;

    while (isPrime(num)) {

 

        // Following three lines generate the next

        // circular permutation of a number. We move

        // last digit to first position.

        int rem = num % 10;

        int div = num / 10;

        num = (pow(10, count - 1)) * rem + div;

 

        // If all the permutations are checked and

        // we obtain original number exit from loop.

        if (num == N)

            return true;

    }

 

    return false;

}

 

// Driver Program

int main()

{

    int N = 1193;

    if (checkCircular(N))

        cout << "Yes" << endl;

    else

        cout << "No" << endl;

    return 0;

}