242.Valid Anagram

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Question

Given two strings s and t , write a function to determine if t is an anagram of s.

Example 1:

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Input: s = "anagram", t = "nagaram"
Output: true

Example 2:

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Input: s = "rat", t = "car"
Output: 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?

Answer

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class Solution {
    public boolean isAnagram(String s, String t) {
        char ss[] = s.toCharArray();
        char tt[] = t.toCharArray();
        Arrays.sort(ss);
        Arrays.sort(tt);
        return Arrays.equals(ss,tt);
    }
}

Running time: depends on the sort algorithm, O(nlogn)

Space: O(n), n the length of String

Better Answer

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