蓝桥杯软件大赛练习系统——算法训练 最小乘积(基本型)

 1 import java.util.Arrays;
 2 import java.util.Comparator;
 3 import java.util.Scanner;
 4 
 5 
 6 public class Main {
 7 
 8     public static void main(String[] args) {
 9         // TODO Auto-generated method stub
10         Scanner cin = new Scanner(System.in);
11         int cas_num = cin.nextInt();
12         for(int cas_idx = 0; cas_idx < cas_num; cas_idx ++) {
13             int num = cin.nextInt();
14             Integer[] arr1 = new Integer[num];
15             Integer[] arr2 = new Integer[num];
16             for(int i = 0; i < num; i ++) {
17                 arr1[i] = cin.nextInt();
18             }
19             
20             for(int i = 0; i < num; i ++) {
21                 arr2[i] = cin.nextInt();
22             }
23             Arrays.sort(arr1);
24             Comparator<Integer> cmp = new MyComparator();
25             Arrays.sort(arr2, cmp);
26             Arrays.sort(arr2);
27             Integer sum = 0;
28             for(int i = 0; i < num; i ++) {
29                 sum += (arr1[i] * arr2[num - i - 1]);
30             }
31             System.out.println(sum);
32         }
33         cin.close();
34         
35     }
36 
37 }
38 class MyComparator implements Comparator<Integer>{
39 
40     @Override
41     public int compare(Integer o1, Integer o2) {
42         // TODO Auto-generated method stub
43         if(o1.compareTo(o2) < 0) {
44             return 1;
45         }else if(o1.compareTo(o2) > 0){
46             return -1;
47         }else {
48             return 0;
49         }
50     }
51 }