#08MediumArrays & Strings · 58% acceptance

Group by Signature

Hash MapStringSorting

Given an array of strings, group the anagrams together. Two strings are anagrams if they contain the same letters in any order.

You bin samples by a normalized signature all the time. The trick here is choosing a good canonical key.

Examples

Input: ["eat","tea","tan","ate","nat","bat"]

Output: [["eat","tea","ate"],["tan","nat"],["bat"]]

Constraints

·1 ≤ strs.length ≤ 10^4
·Strings are lowercase a–z.

Hints

solution.pyPython 3

from collections import defaultdict

def group_anagrams(strs):
    buckets = defaultdict(list)
    for w in strs:
        key = "".join(sorted(w))
        buckets[key].append(w)
    return list(buckets.values())

Test console

// hit Run to execute the sample tests

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