Double Every Prime Digit and Append to the Number

The program must accept an integer N as the input. The task is to double the value of every prime digit in N and then append those values to N itself.

Boundary Condition(s):
10 <= N <= 10^8

Input Format:
The first line contains the integer N.

Output Format:
A single line contains the modified number.

Example Input/Output 1:
Input:
4352

Output:
435246

Explanation:
The prime digits in 4352 are 3, 5, and 2. When doubled, they become 6, 10, and 4. Appending 6 and 4 to the original number (since 10 is not a single-digit), we get 435246.

Example Input/Output 2:
Input:
2178

Output:
217842146

Explanation:
The prime digits in 2178 are 2 and 7. When doubled, they become 4 and 14. Appending 4 and both digits of 14 to the original number, we get 217842146.

Example Input/Output 3:
Input:
4910

Output:
491082

Explanation:
The prime digits in 4910 are 4, 9, and 1. None of them are prime numbers, so no digits are appended to the original number. The output remains 4910.

N = input().strip()
prime_digits = {'2', '3', '5', '7'}
appended = ''.join(str(2*int(d)) if d in prime_digits else '' for d in N)
print(N + appended)

#include<stdio.h>
#include<string.h>

int isPrimeDigit(char d) {
    return d == '2' || d == '3' || d == '5' || d == '7';
}

int main() {
    char N[10];
    scanf("%s", N);
    printf("%s", N);
    for(int i = 0; N[i]; i++) {
        if(isPrimeDigit(N[i])) {
            printf("%d", 2 * (N[i] - '0'));
        }
    }
    return 0;
}

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

bool isPrimeDigit(char d) {
    return d == '2' || d == '3' || d == '5' || d == '7';
}

int main() {
    string N;
    cin >> N;
    cout << N;
    for(char c : N) {
        if(isPrimeDigit(c)) {
            cout << 2 * (c - '0');
        }
    }
    return 0;
}

import java.util.Scanner;

public class DoublePrimeDigits {
    static boolean isPrimeDigit(char d) {
        return d == '2' || d == '3' || d == '5' || d == '7';
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String N = sc.next();
        System.out.print(N);
        for(char c : N.toCharArray()) {
            if(isPrimeDigit(c)) {
                System.out.print(2 * (c - '0'));
            }
        }
    }
}