> For the complete documentation index, see [llms.txt](https://maksimdan.gitbook.io/interview-practice-problems/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://maksimdan.gitbook.io/interview-practice-problems/leetcode_sessions/49_group_anagrams.md).

# 49 Group Anagrams

Given an array of strings, group anagrams together.

For example, given: \["eat", "tea", "tan", "ate", "nat", "bat"], Return:

```
[
  ["ate", "eat","tea"],
  ["nat","tan"],
  ["bat"]
]
```

Note: All inputs will be in lower-case.

* Algorithm:
  * Map each sorted word (key) to its actual word (vector of values).
  * Thats it

```cpp
vector<vector<string>> groupAnagrams(vector<string>& strs) {
    unordered_map<string, vector<string>> map;

    for (auto str : strs) {
        string word = str;
        sort(str.begin(), str.end());

        //auto &found = map.find(str);
        if (map.find(str) == map.end()) {
            map.insert({ { str },{ word } });
        }
        else {
            map.find(str)->second.push_back(word);
        }
    }

    vector<vector<string>> anagrams;
    for (auto i : map) {
        anagrams.push_back(i.second);
    }

    return anagrams;
}

int main() {
    vector<string> strs = {
        "eat", "tea", "tan", "ate", "nat", "bat"
    };

    print2d(groupAnagrams(strs));

}
```