package question;

/**
 * @author Roderland
 * @since 1.0
 */
public class Question765 {
 public static void main(String[] args) {
 int[] ints = {
 5, 4, 2, 6, 3, 1, 0, 7
 };
 System.out.println(new Question765().minSwapsCouples(ints));
 }

 public int minSwapsCouples(int[] row) {
 int[] address = new int[row.length];
 for (int i = 0; i < row.length; i++) {
 address[row[i]] = i;
 }
 int res = 0;
 for (int i = 0; i < row.length; i += 2) {
 int tar;
 if (row[i] % 2 == 0) {
 tar = row[i] + 1;
 } else {
 tar = row[i] - 1;
 }
 if (address[tar] == i + 1) continue;
 int tarAddress = address[tar];
 int index = row[i + 1];
 row[tarAddress] = row[i + 1];
 row[i + 1] = tar;
 address[tar] = i + 1;
 address[index] = tarAddress;
 res++;
 }
 return res;
 }
}