/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
 public static boolean isAnagram(String s, String t) {
 if (s.length() != t.length()) return false;
 
        HashMap<Character, Integer> map = new HashMap<>();
 
        // Count frequency of each character in string s
        for (char c : s.toCharArray()) {
            map.put(c, map.getOrDefault(c, 0) + 1);
        }
 
        // Subtract frequency using string t
        for (char c : t.toCharArray()) {
            if (!map.containsKey(c)) return false;
            map.put(c, map.get(c) - 1);
            if (map.get(c) == 0) map.remove(c);
        }
 
        // If map is empty, it's a valid anagram
        return map.isEmpty();
    }
 
    public static void main(String[] args) {
        System.out.println(isAnagram("listen", "silent")); // true
        System.out.println(isAnagram("hello", "world"));   // false
    }
}
 
 

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