LeetCode : Valid Anagram

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

For example,
s = “anagram”, t = “nagaram”, return true.
s = “rat”, t = “car”, return 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?

class Solution {
public:
    bool isAnagram(string s, string t) {
        if(s.length()==0&&t.length()==0)
             return true;
        sort(s.begin(),s.end());
        sort(t.begin(),t.end());
        if(s.compare(t)==0)
            return true;
        else
            return false;
    }
};