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:

Solution

# @param {Integer} x
# @return {Integer}
def reverse(x)
  new_a = x.to_s.reverse.to_i
  if x >= 0
    new_a < (2 ** 31 - 1) ? new_a : 0
  else
    -new_a > (-2) ** 31 ? -new_a : 0
  end
end