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?

这道题tag上有hashtable，第一反应用hashmap类，其实这是让用hashtable的思想，比如用int[26] 的数组存s中各个字母出现的次数，然后遍历t 中的各个字母减去对应的int[26]存的次数。代码如下：

public class Solution {
public boolean isAnagram(String s, String t) {
if (s.length() != t.length()) {
return false;
}
int[] charmap = new int[26];
for (int i = 0; i < s.length(); i++) {
charmap[s.charAt(i) - 'a'] ++;
charmap[t.charAt(i) - 'a'] --;
}
for (int count:charmap) {
if(count != 0) {
return false;
}
}
return true;
}
}