Valid Anagarm

Problem:

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.

Analysis:

Use int[26] to store the word. First round add, second round minus. Then check if there is 0 in int[26].

Solution:

class Solution {
    public boolean isAnagram(String s, String t) {
        int[] map = new int[26];
        for (char c: s.toCharArray()) {
            map[c - 'a']++;
        }
        for (char c: t.toCharArray()) {
            map[c - 'a']--;
        }
        for (int n: map) {
            if (n != 0) return false;
        }
        return true;
    }
}