Group Anagrams

• Time : O(n)
• Space : O(n)

#include <vector>

using namespace std;

vector<vector<string>> groupAnagrams(vector<string> words) {
	unordered_map<string, vector<string>> mp;
	for(auto& w : words) {
		string s = w;
		sort(begin(s), end(s));
		mp[s].push_back(w);
	}
	vector<vector<string>> res;
	for(auto& [_, g] : mp) res.push_back(g);
	return res;
}