Leetcode•Apr 09, 2025

Reverse Integer

Hazrat Ali

Leetcode

Given a signed 32-bit integer x, return x with its digits reversed. If reversing x causes the value to go outside the signed 32-bit integer range [-231, 231 - 1], then return 0.

Assume the environment does not allow you to store 64-bit integers (signed or unsigned).

 

Example 1:

Input: x = 123
Output: 321

Example 2:

Input: x = -123
Output: -321

Example 3:

Input: x = 120
Output: 21


Solution
/**
 * @param {number} x
 * @return {number}
 */
const reverse = x => {
  const MAX = Math.pow(2, 31) - 1;
  const MIN = -Math.pow(2, 31);

  let res = 0;

  while (x !== 0) {
    res = res * 10 + (x % 10);
    x = parseInt(x / 10);

    if (res > MAX || res < MIN) {
      return 0;
    }
  }

  return res;
};







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