> For the complete documentation index, see [llms.txt](https://liuyang89116.gitbook.io/my-leetcode-book/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://liuyang89116.gitbook.io/my-leetcode-book/post_chapter_2_math/problem_389_find_the_difference.md).

# Problem 389: Find the Difference

> <https://leetcode.com/problems/find-the-difference/>

## 思路

* 使用异或关系判断

```java
public class Solution {
    public char findTheDifference(String s, String t) {
        char ans = 0;
        for (int i = 0; i < s.length(); i++) {
            ans ^= s.charAt(i);
        }
        for (int i = 0; i < t.length(); i++) {
            ans ^= t.charAt(i);
        }

        return ans;
    }
}
```