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?

判断t是不是s的排列之一

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