[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?

Thought process:

Iterate through both strings, count the number of each character, and compare the counts.

Solution:

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

Time complexity: O(s + t).

Follow-up: initialize count array to have a length of 256.