2. 코드

import java.util.Arrays;
 
public class TryHelloWorld {
 
  public static void main(String[] args) {
    int[] A = { 1, 2, 3 };
    int[] B = { 4, 5, 6 };
 
    TryHelloWorld test = new TryHelloWorld();
    System.out.println("## result=" + test.getMinSum(A, B));
  }
 
  public int getMinSum(int[] A, int[] B) {
    int answer = 0;
 
    Arrays.sort(A);
    Arrays.sort(B);
 
    for (int inx = 0; inx < A.length; inx++) {
      answer += A[inx] * B[B.length - 1 - inx];
    }
 
    return answer;
  }
}