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?

判断一个串的字母打乱顺序后，是否等于另一个串

C++(12ms):

class Solution {
public:
    bool isAnagram(string s, string t) {
        if (s.size() != t.size())
            return false ;
        vector<int> vec(128,0) ;
        for(char c : s){
            vec[c-'a']++ ;
        }
        for(char c : t){
            if (--vec[c-'a'] < 0)
                return false ;
        }
        return true ;
    }
};