242. Valid Anagram

Given two strings s and t, return true if t is an anagram of s, and false otherwise.

An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.

Follow up: What if the inputs contain Unicode characters? How would you adapt your solution to such a case?

• we can use map rather then integer array

class Solution {
public:
    bool isAnagram(string s, string t) {
        int arr[26]{0};
        for(auto& ch : s) ++arr[ch-'a'];
        for(auto& ch : t) --arr[ch-'a'];

        for(int i = 0; i < 26; i++)
            if(arr[i]) return false;
        return true;
    }
};