Leetcode 7. Reverse Integer

Posted 2021-03-11 Steve Yu

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.

这道题目考察了字符的反转，注意点是，我们需要进行判断是否溢出，我们直接强制转换一下即可

class Solution {
public:
    int reverse(int x) {
        long ans = 0;
        while(x != 0) {
            ans = ans * 10 + x % 10;
            x /= 10;
        }
        return (int)ans == ans ? ans: 0;
    }
};