Leetcode 7. Reverse Integer（水）

7. Reverse Integer

Easy

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 fl = ;
         if(x >= pow(,) || x <= -pow(,)) return ;
         if(x<=){
             fl = ;
             x = -x;
         }
         long long ans = ;
         while(x>){
             ans = ans *  + (x%);
             if(ans >= pow(,)) return ;
             x = x/;
         }
         if(fl==) ans = -ans;
         return ans;
     }
 };