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Notes

• 0242. Valid Anagram
  • Approach
  • C++

DONE 0242. Valid Anagram   easy arrays hashing counting

Approach

Frequency counter with fixed-size array (Alpha Frequency Array trick). Early exit on size mismatch. Single pass over both strings.

C++

class Solution {
public:
  bool isAnagram(std::string s, std::string t) {
    if (s.size() != t.size()) return false;
    std::array<int, 26> freq{};
    for (int i = 0; i < s.size(); i++) {
      freq[s[i] - 'a']++;
      freq[t[i] - 'a']--;
    }
    return std::all_of(freq.begin(), freq.end(), [](int x){ return x == 0; });
  }
};