算法训练 最小乘积(基本型)

import java.util.Arrays;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner in = new Scanner(System.in);
        int cnt = in.nextInt();
        for ( int i = 0 ; i < cnt ; i++){
            int len1 = in.nextInt();
            int[] arr1 = new int[len1];
            int[] arr2 = new int[len1];
            for ( int j = 0 ; j < len1 ; j++){
                arr1[j] = in.nextInt();
            }
            for ( int j = 0 ; j < len1 ; j++){
                arr2[j] = in.nextInt();
            }
            Arrays.sort(arr1);
            Arrays.sort(arr2);
            int min = 0;
            for ( int j = 0 ; j < len1 ; j++){
                min += arr1[j] * arr2[len1-j-1];
            }
            System.out.println(min);
        }
        in.close();
    }

}