Reverse Integer Easy 0 attempts
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Reverse Integer

Easy MatrixBFSDFS LeetCode

You're given a signed 32-bit integer x. Reverse the order of its digits and return the result. If reversing would push the value outside the signed 32-bit range, return 0 instead.

Input Format
Implement reverse(x). Inputs below show JavaScript function arguments; there is no stdin parsing.
Output Format
Return the result described in the statement.

Sample Input and Output

Example 1 ยท Run Sample

Input
x = 123
Output
321

Example 2

Input
x = -123
Output
-321

Example 3

Input
x = 120
Output
21
Constraints
  • -2^31 <= x <= 2^31 - 1
Test Cases (3)
Case 1
Args: [123] Expected: 321
Case 2
Args: [-123] Expected: -321
Case 3
Args: [120] Expected: 21
Topics
MatrixBFSDFS

Pop and Push Digits

javascript
function reverse(x) {
  let result = 0;
  while (x !== 0) {
    result = result * 10 + x % 10;
    x = Math.trunc(x / 10);
  }
  return result > 2**31 - 1 || result < -(2**31) ? 0 : result;
}

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

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JavaScript