Reverse Integer -leetcode

最新推荐文章于 2020-05-01 17:53:02 发布

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本文探讨了如何通过编程实现整数反转，并处理边界条件如溢出和特殊数字如末尾为0的情况。

Reverse Integer

AC Rate: 1290/3061

My Submissions

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).

没有考虑溢出情况-:)

class Solution {
public:
    int reverse(int x) {
        // Note: The Solution object is instantiated only once and is reused by each test case.
        bool sign = x < 0 ? true : false;
        unsigned int tx = sign ? -x : x;
        unsigned int ans = 0;
        while (tx) {
            ans *= 10;
            ans += tx % 10;
            tx /= 10;
        }
        return (sign ? -ans : ans);
    }
};