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 res = 0; while(x) { int tmp = res*10 + x%10; if(tmp/10 != res) return 0; // trick! res = tmp; x /= 10; } return res; } }; class Solution { public: int reverse(int x) { int origX = x; long res = 0; while(x) { res = res*10 + x%10; if(res>INT_MAX || res<INT_MIN) return 0; // use MACRO x/=10; } return res; } };
原文：https://www.cnblogs.com/BlackYao/p/12143010.html