Medium
Hashing & Frequency Maps
Group Anagrams
Give every anagram the same canonical key.
Approach
Anagrams share a canonical form — either the sorted string or a 26-length count tuple. Use that form as a hash-map key and append each word to its bucket. The count-tuple key gives O(n·k) versus O(n·k log k) for sorting.
Time complexity
O(n·k)
Space complexity
O(n·k)
Common mistake
Using a mutable list as a dict key — keys must be hashable, so use a tuple or string.
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