49. Group Anagrams

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

Example 1:
Input: strs = ["eat","tea","tan","ate","nat","bat"]
Output: [["bat"],["nat","tan"],["ate","eat","tea"|"bat"],["nat","tan"],["ate","eat","tea"]]

Explanation:

• There is no string in strs that can be rearranged to form "bat".
• The strings "nat" and "tan" are anagrams as they can be rearranged to form each other.
• The strings "ate", "eat", and "tea" are anagrams as they can be rearranged to form each other.

Example 2:
Input: strs = [""]
Output: ""

Example 3:
Input: strs = ["a"]
Output: "a"

def groupAnagrams(self, strs: List[str]) -> List[List[str]]:
    d = {}
    finalls = {}
    setno = -1
    res = []

    for word in strs:
        if len(word) == 0:
            if 'blank' in finalls:
                finalls['blank'].append("")
            else:
                finalls['blank'] = [""]
            continue

        flag = 0
        allsets = []

        for ch in word:
            if ch not in d:
                flag = 1
                break

        if flag != 1:
            for ch in word:
                allsets.append(d[ch])
        else:
            setno += 1
            for ch in word:
                if ch in d:
                    d[ch].add(setno)
                else:
                    d[ch] = {setno}
            finalls[setno] = [word]
            continue

        result = set.intersection(*allsets).pop()
        if result in finalls:
            finalls[result].append(word)
        else:
            finalls[result] = [word]

    for ls in finalls.values():
        res.append(ls)

    return res