Sample Input 

2
2 2 4 
3 2 4 6

Sample Output 

2
4

大意:有個黑道老大想要住在離他所有親友最近的地方，給你一些親友的位址，問住在哪個街道上是最近的

解法:中位數



import java.util.*;

public class UVA10041 {

 public static void main(String[] args) {

  Scanner sc = new Scanner(System.in);

  int N = sc.nextInt();

  for (int i = 0; i < N; i++) {

   int r = sc.nextInt();

   int house[] = new int[r];

   for (int j = 0; j < r; j++) {

    house[j] = sc.nextInt();

   }
   Arrays.sort(house);

   int median = house[r / 2];

   int sum = 0;

   for (int k = 0; k < r; k++) {
    sum += Math.abs(house[k] - median);
   }

   System.out.println(sum);

  }

 }

}