[LeetCode]Reverse Integer

Reverse digits of an integer.

Example1: x =  123, return  321 Example2: x = -123, return -321

click to show spoilers.

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).

思考:此题想要AC并不难,关键在于自己是否想到到splilers中说的那些注意点。

class Solution {
public:
    int reverse(int x) {
        // IMPORTANT: Please reset any member data you declared, as
        // the same Solution instance will be reused for each test case.
		int res = 0;  
		while(x)  
		{  
			res = res*10 + x%10;  
			x /= 10;  
		}  
		return res;  
	}
};

 

posted @ 2013-11-07 11:29  七年之后  阅读(161)  评论(0编辑  收藏  举报