7. Reverse Integer
难度:Easy
刷题内容
原题连接
- https://leetcode.com/problems/reverse-integer/
内容描述
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.
解题方案
思路 1 - 时间复杂度: O(n)- 空间复杂度: O(1)**
class Solution {
public:
int reverse(int x) {
long long val = 0;
do
{
val = val * 10 + x % 10;
x /= 10;
} while (x);
return (val > INT_MAX || val < INT_MIN) ? 0 : val;
}
};
