LeetCode_Reverse Integer

Reverse Integer

 

Reverse digits of an integer.

Example1: x = 123, return 321
Example2: x = -123, return -321
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?
For the purpose of this problem, assume that your function returns 0 when the reversed integer overflows.
Update (2014-11-10):

Test cases had been added to test the overflow behavior.
题目要求实现对一个int类型的数字进行翻转，需要注意的是翻转之后的数字可能出现越界（经过测试，如果越界，系统希望输出数字0，不越界则正常输出）
java解题：
public int reverse(int x) {
long result = 0; //这里要声明long型的，因为该数在不断计算过程中可能超过int的范围
while (x != 0) {
result = result * 10 + x % 10; //最重要的逻辑
if(result>Integer.MAX_VALUE || result<Integer.MIN_VALUE)//加上越界判断
return 0;
x = x / 10;
}
return (int) result; //注意类型转换
}