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 hold integers within the 32-bit signed integer range. For the purpose of this problem, assume that your function returns 0 when the reversed integer overflows.
详见:https://leetcode.com/problems/reverse-integer/description/
实现语言:Java
class Solution { public int reverse(int x) { int res = 0; while (x != 0) { if (res > Integer.MAX_VALUE / 10 || res < Integer.MIN_VALUE / 10) { return 0; } res = res * 10 + x % 10; x /= 10; } return res; } }
实现语言:C++
class Solution { public: int reverse(int x) { long res=0; while(x) { res=res*10+x%10; x/=10; } return (INT_MAX<res||INT_MIN>res)?0:res; } };