242. Valid Anagram

Given two strings s and t , write a function to determine if t is an anagram of s.

Example 1:

Input: s = "anagram", t = "nagaram"
Output: true

Example 2:

Input: s = "rat", t = "car"
Output: false

Note:
You may assume the string contains only lowercase alphabets.

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

Approach 1# Sorting: 

class Solution {
public:
    bool isAnagram(string s, string t) {
        if (s.length() != t.length()) return false;
        sort(s.begin(), s.end());
        sort(t.begin(), t.end());
        for (int i = 0; i < s.length(); ++i) {
            if (s[i] != t[i])
                return false;
        }
        return true;
    }
};

Runtime: 28 ms

Approach 2# Hash Table:

class Solution {
public:
    bool isAnagram(string s, string t) {
        if (s.length() != t.length()) return false;
        vector<int> temp(26, 0);
        for (int i = 0; i < s.length(); ++i) {
            temp[s[i]-'a']++;
            temp[t[i]-'a']--;
        }
        for (int i = 0; i < 26; ++i) {
            if (temp[i] != 0) return false;
        }
        return true;
    }
};

Runtime: 8 ms, faster than 83.11% of C++ online submissions for Valid Anagram.