PalindromePrime.java

packagecom.thealgorithms.misc;

importjava.util.ArrayList;
importjava.util.List;

publicfinalclassPalindromePrime {
privatePalindromePrime() {
 }

publicstaticbooleanprime(intnum) {
if (num < 2) {
returnfalse; // Handle edge case for numbers < 2
 }
if (num == 2) {
returntrue; // 2 is prime
 }
if (num % 2 == 0) {
returnfalse; // Even numbers > 2 are not prime
 }

for (intdivisor = 3; divisor <= Math.sqrt(num); divisor += 2) {
if (num % divisor == 0) {
returnfalse;
 }
 }
returntrue;
 }

publicstaticintreverse(intn) {
intreverse = 0;
while (n != 0) {
reverse = reverse * 10 + (n % 10);
n /= 10;
 }
returnreverse;
 }

publicstaticList<Integer> generatePalindromePrimes(intn) {
List<Integer> palindromicPrimes = newArrayList<>();
if (n <= 0) {
returnpalindromicPrimes; // Handle case for 0 or negative input
 }

palindromicPrimes.add(2); // 2 is the first palindromic prime
intcount = 1;
intnum = 3;

while (count < n) {
if (num == reverse(num) && prime(num)) {
palindromicPrimes.add(num);
count++;
 }
num += 2; // Skip even numbers
 }
returnpalindromicPrimes;
 }
}