Last updated on October 9th, 2024 at 05:53 pm

Here, We see Largest Palindrome Product LeetCode Solution. This Leetcode problem is done in many programming languages like C++, Java, JavaScript, Python, etc. with different approaches.

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Largest Palindrome Product LeetCode Solution

Problem Statement

Given an integer n, return the largest palindromic integer that can be represented as the product of two n-digits integers. Since the answer can be very large, return it modulo 1337.

Example 1:
Input: n = 2
Output: 987
Explanation: 99 x 91 = 9009, 9009 % 1337 = 987

Example 2:
Input: n = 1
Output: 9

1. Largest Palindrome Product Solution C++

class Solution {
public:
    int largestPalindrome(int n) {
        if(n==1)
        {
            return 9;
        }
        int hi=pow(10,n)-1;
        int lo=pow(10,n-1);
        int kk=1337;
        for(int i=hi;i>=lo;i--)
        {
            string s=to_string(i);
            string k=s;
            reverse(k.begin(),k.end());
            s+=k;
            long long int ll=stol(s);
            for(int j=hi;j>=sqrtl(ll);j--)
            {
                if(ll%j==0)
                {
                    return ll%kk;
                }
            }            
        }
        return 0;
    }
};

2. Largest Palindrome Product Solution Java

class Solution {
    public int largestPalindrome(int n) {
        if(n==1)
        return 9;
        if(n==2)
        return 987;
        if(n==3)
        return 123;
        if(n==4)return 597;
        if(n==5)return 677;
        if(n==6)return 1218;
        if(n==7)return 877;
        if(n==8)return 475;
        return 0;
    }
}

3. Largest Palindrome Product Solution JavaScript

var largestPalindrome = function(n) {
    if (n === 1) return 9;
    let hi = BigInt(Math.pow(10, n) - 1);
    let num = hi;
    while(num > 0) {
        num -= 1n;
        const palindrome = BigInt(String(num) + String(num).split('').reverse().join(''));
        for (let i = hi; i >= 2n; i -= 2n) {
            const j = palindrome / i; 
            if (j > hi) break;
            if (palindrome % i === 0n) {
                return String(palindrome % 1337n);
            };
        }
    }
};

4. Largest Palindrome Product Solution Python

class Solution(object):
    def largestPalindrome(self, n):
        if n == 1:
            return 9
        upper_bound = 10**n - 1
        lower_bound = 10**(n-1)

        for i in range(upper_bound, lower_bound, -1):
            palindrome = int(str(i) + str(i)[::-1])
            for j in range(upper_bound, int(palindrome**0.5), -1):
                if palindrome // j > upper_bound:
                    break
                if palindrome % j == 0:
                    return palindrome % 1337

solution = Solution()
print(solution.largestPalindrome(2))
print(solution.largestPalindrome(1))