Anagram

Two strings,  and , are called anagrams if they contain all the same characters in the same frequencies. For this challenge, the test is not case-sensitive.
For example, the anagrams of CAT are CAT, ACT, tac, TCA, aTC, and CtA.

Solution:

import java.io.*;
import java.util.*;

public class Solution {
    public static String IsAnagram(String s1,String s2){
        s1=s1.replaceAll("\\s", "").toLowerCase();
        s2=s2.replaceAll("\\s", "").toLowerCase();
        
        if(s1.length() != s2.length()){
            return "Not Anagrams";
        }
        int[] letter=new int[26];
        for(int i=0;i<s1.length();i++){
            int index1 = s1.charAt(i) - 'a';
            int index2 = s2.charAt(i) - 'a';
            letter[index1]++;
            letter[index2]--;
        }
        for(int count:letter){
            if(count!=0){
                return "Not Anagrams";
            }
        }
        return "Anagrams";
        
    }

    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        String s1=sc.nextLine();
        String s2=sc.nextLine();
        System.out.println(IsAnagram(s1,s2));
    }
}