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; } };