문제: https://school.programmers.co.kr/learn/courses/30/lessons/12941
import java.util.*;
class Solution
{
public int solution(int []A, int []B)
{
int len = A.length;
Arrays.sort(A);
Arrays.sort(B);
int answer = 0;
for(int i = 0; i < len; i++){
answer += A[i] * B[len-1-i];
}
return answer;
}
}