> 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/chapter_1_combination_and_permutation/problem-320-generalized-abbreviation.md).

# Problem 320: Generalized Abbreviation

> <https://leetcode.com/problems/generalized-abbreviation/#/description>

![](/files/-Lpv9v2xrygaRsOmR0qX)

## 思路

* 对每个 character 来说，有两种情况：取或者不取。
* 对于每个 dfs，也有两种情况：count 增加，或者从 0 开始。

```java
public class Solution {
    public List<String> generateAbbreviations(String word) {
        List<String> rst = new ArrayList<>();
        dfs(word, "", 0, 0, rst);

        return rst;
    }

    private void dfs(String word, String cur, int pos, int count, List<String> rst) {
        if (pos == word.length()) {
            if (count > 0) cur += count;
            rst.add(cur);
            return;
        } 

        dfs(word, cur, pos + 1, count + 1, rst);
        dfs(word, cur + (count > 0 ? count : "") + word.charAt(pos), pos + 1, 0, rst);
    }
}
```