## 1. Problem

Given an array of strings strs, group the anagrams together. You can return the answer in any order.

An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.

**Example 1:**

```
Input: strs = ["eat","tea","tan","ate","nat","bat"]
Output: [["bat"],["nat","tan"],["ate","eat","tea"]]
```

**Example 2:**

```
Input: strs = [""]
Output: [[""]]
```

**Example 3:**

```
Input: strs = ["a"]
Output: [["a"]]
```

**Constraints:**

- 1 <= strs.length <= 10^4
- 0 <= strs[i].length <= 100
- strs[i] consists of lowercase English letters.

## 2. Solution

I solved this problem like this.

- Put s value(each str == s) on dic. The key is sorted(s).
- Put dic values on ans list.

```
class Solution:
def groupAnagrams(self, strs: List[str]) -> List[List[str]]:
dic = {}
for s in strs:
key = ''.join(sorted(s))
if key not in dic:
dic[key] = []
dic[key].append(s)
ans = []
for key in dic:
ans.append(dic[key])
return ans
```