【Leetcode】Reverse Integer

题目：

Reverse digits of an integer.

Example1: x = 123, return 321

Example2: x = -123, return -321

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Have you thought about this?
Here are some good questions to ask before coding. Bonus points for you if you have already thought through this!
If the integer's last digit is 0, what should the output be? ie, cases such as 10, 100.
Did you notice that the reversed integer might overflow? Assume the input is a 32-bit integer, then the reverse of 1000000003 overflows. How should you handle such cases?
Throw an exception? Good, but what if throwing an exception is not an option? You would then have to re-design the function (ie, add an extra parameter).

解题思路：将输入数据的数字从右往左取出，再从左往右排成输出数据。主要用到取模和乘除运算。需要注意溢出的可能性（因此添加了一句防止溢出的代码）
代码：

class Solution {
public:
int reverse(int x) {
int result=0;
while(x!=0){
result=result*10+x%10;
if(result>INT_MAX/10||(result==INT_MAX/10&&(x/10)%10>INT_MAX%10))return 0;//prevent overflow
x/=10;
}
return result;
}
};