Leetcode 7 Reverse Integer
阿新 • • 發佈:2018-12-13
Given a 32-bit signed integer, reverse digits of an integer.
Example 1:
Input: 123 Output: 321
Example 2:
Input: -123 Output: -321
Example 3:
Input: 120 Output: 21
Note: Assume we are dealing with an environment which could only store integers within the 32-bit signed integer range: [−231, 231 − 1]. For the purpose of this problem, assume that your function returns 0 when the reversed integer overflows.
class Solution { public int reverse(int x) { int result = 0; while (x != 0) { int mod = x % 10; x = x / 10; if (result > Integer.MAX_VALUE / 10 || result < Integer.MIN_VALUE / 10) return 0; result = result * 10 + mod; } return result; } }
為了防止溢位,在運算中應該加以判斷進行標記,如果溢位那麼直接返回。