LeetCode 242. 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) {        int count[26] = {0};        int len1 = s.size(), len2 = t.size();        int i;        for(i = 0; i < len1; i ++){            count[s[i] - 'a'] ++;        }        for(i = 0; i < len2; i ++){            count[t[i] - 'a'] --;        }        for(i = 0; i < 26; i ++){            if(count[i] != 0) return false;        }        return true;    }};