reverse interger

最新推荐文章于 2021-02-24 02:18:50 发布

原创最新推荐文章于 2021-02-24 02:18:50 发布 · 776 阅读

0 ·

CC 4.0 BY-SA版权

number process 专栏收录该内容

17 篇文章

订阅专栏

本文介绍了一种用于翻转整数的算法，并提供了详细的C++实现代码。文章讨论了特殊情况处理，如输入整数末尾为0的情况及整数翻转后可能发生的溢出问题。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

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?

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).
这里可以用abs 把interger转换成string，然后处理。

class Solution {
public:
    int reverse(int x) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        int flag = x <0 ? -1 : 1;
        int result = 0;
        while (x)
        {
            result = result*10 + abs (x%10);
            x /= 10;
        }
        result *= flag;
        return result;
    }
};

注意： -123%10 = -3！！！！！！！！！！！