Palindrome Number | Problems

Given an integer x, return true if it's a palindrome (reads the same backward as forward).

Example: x = 121 → true, x = -121 → false

Sample Input

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Sample Output

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Constraints

-2^31 <= x <= 2^31 - 1

Test Cases

Case 1

Args: [121] Expected: true

Case 2

Args: [-121] Expected: false

Case 3

Args: [10] Expected: false

Topics

Matrix BFS DFS

Reverse Half

function isPalindrome(x) {
  if (x < 0 || (x % 10 === 0 && x !== 0)) return false;
  let rev = 0;
  while (x > rev) { rev = rev * 10 + x % 10; x = Math.floor(x / 10); }
  return x === rev || x === Math.floor(rev / 10);
}

Time: O(log n) | Space: O(1)

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