LeetCode笔记 – Reverse Integer

题目描述：

Given a 32-bit signed integer, reverse digits of an integer.

Example:

Input: 123
Output: 321

Input: -123
Output: -321

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) {
       if(x == 0) {
           return 0;
       }
        bool flag = x > 0;
        x = std::abs(x);
        long result = 0;
        while(x > 0) {
            result = result * 10 + x % 10;
            x /= 10;
        }
        
        if(!flag) {
            result = -result;
        }
        
        if(result > INT_MAX || result < INT_MIN) {
            return 0;
        }
        
        return (int) result;
    }
};