javahash2.java

import java.io.*;
import java.util.*;
public class Solution {
    
    private static boolean isAnagram(String a, String b) {
        char[] a_arr = a.toCharArray();
        char[] b_arr = b.toCharArray();
        Arrays.sort(a_arr);
        Arrays.sort(b_arr);
        String sorted_a = new String(a_arr);
        String sorted_b = new String(b_arr);
        return a.equals(b);
    }
    
    private static void computeAnagramDistance(String a, String b) {
        if (a.length() != b.length()) {
            System.out.println(-1);
            return;
        } else if (isAnagram(a, b)) {
            System.out.println(0);
            return;
        }
        
        HashMap<Character, Integer> a_map = new HashMap<>();
        for (Character c : a.toCharArray()) {
            if (a_map.containsKey(c)) {
                a_map.put(c, a_map.get(c) + 1);
            } else {
                a_map.put(c, 1);
            }
        }
        
        for (Character c : b.toCharArray()) {
            if (a_map.containsKey(c)) {
                a_map.put(c, a_map.get(c) - 1);
            } else {
                a_map.put(c, -1);
            }
        }
        
        Integer answer = 0;
        for (Integer i : a_map.values()) {
            if (i != 0) {
                answer += Math.abs(i);
            }
        }
        System.out.println(answer/2);
    }
    
    public static void main(String args[] ) throws Exception {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT */
        Scanner cin = new Scanner(System.in);
        int lines = cin.nextInt();
        while (lines > 0) {
            String a_concat_b = cin.next();
            String a = a_concat_b.substring(0, (a_concat_b.length())/2);
            String b = a_concat_b.substring((a_concat_b.length())/2);
            computeAnagramDistance(a, b);
            lines -= 1;
        }
    }
}