Find the largest palindrome made from the product of two n-digit numbers.
Since the result could be very large, you should return the largest palindrome mod 1337.
Example:
Input: 2
Output: 987
Explanation: 99 x 91 = 9009, 9009 % 1337 = 987
Note:
The range of n is [1,8].
public class Palindrome {
public static void main(String[] args) {
for (int n = 1; n <= 8; n++) {
System.out.println(Solution.largestPalindrome(n));
}
}
public static class Solution {
public static int largestPalindrome(int n) {
if (n == 1) {
return 9;
}
int high = (int) Math.pow(10D, n * 1D) - 1;
int low = high / 10;
for (int i = high; i > low; i--) {
long palindrome = getPalindrome(i);
for (long j = high; j > low; j--) {
if (palindrome / j > high) {
break;
}
if (palindrome % j == 0) {
return (int) (palindrome % 1337);
}
}
}
return -1;
}
private static long getPalindrome(int num) {
return Long.parseLong(num + (new StringBuilder(String.valueOf(num))).reverse().toString());
}
}
}
