LeetCode-in-All
7. Reverse Integer
Medium
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
Example 4:
Input: x = 0
Output: 0
Constraints:
-231 <= x <= 231 - 1
Solution
/**
* @param {number} x
* @return {number}
*/
var reverse = function (x) {
let rev = 0
while (x !== 0) {
rev = rev * 10 + (x % 10)
x = Math.trunc(x / 10)
}
if (rev > Math.pow(2, 31) - 1 || rev < -Math.pow(2, 31)) {
return 0
}
return rev
}
export { reverse }