LeetCode - Reverse Integer

最新推荐文章于 2026-01-03 03:21:30 发布

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文章标签：

#leetcode #integer

本文介绍了一种用于反转整数的有效算法，并提供了C++实现代码。该算法通过不断获取输入整数的最后一位数字并将其添加到新数字的末尾来完成反转过程。需要注意的是，在实现过程中要特别注意整数溢出的情况。

Reverse digits of an integer.

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

http://oj.leetcode.com/problems/reverse-integer/

Solution:

Start from the last digit which is the input % 10, then add to the previous res times 10

Be careful about the overflow condition, can ask the interviewer for further details

https://github.com/starcroce/leetcode/blob/master/reverse_int.cpp

// 36 ms for 1020 test cases
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 digit = 0, newNum = 0;
        while(x != 0) {
            digit = x % 10;
            newNum = newNum * 10 + digit;
            x = x / 10;
        }
        return newNum;
    }
};