1.2 KiB
1.2 KiB
id | title | challengeType | forumTopicId |
---|---|---|---|
5900f3701000cf542c50fe83 | Problem 4: Largest palindrome product | 5 | 302065 |
--description--
A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 × 99.
Find the largest palindrome made from the product of two n
-digit numbers.
--hints--
largestPalindromeProduct(2)
should return a number.
assert(typeof largestPalindromeProduct(2) === 'number');
largestPalindromeProduct(2)
should return 9009.
assert.strictEqual(largestPalindromeProduct(2), 9009);
largestPalindromeProduct(3)
should return 906609.
assert.strictEqual(largestPalindromeProduct(3), 906609);
--seed--
--seed-contents--
function largestPalindromeProduct(n) {
return true;
}
largestPalindromeProduct(3);
--solutions--
const largestPalindromeProduct = (digit)=>{
let start = 1;
let end = Number(`1e${digit}`) - 1;
let palindrome = [];
for(let i=start;i<=end;i++){
for(let j=start;j<=end;j++){
let product = i*j;
let palindromeRegex = /\b(\d)(\d?)(\d?).?\3\2\1\b/gi;
palindromeRegex.test(product) && palindrome.push(product);
}
}
return Math.max(...palindrome);
}