Java答案（考试忘记加break...，谢评论区答案）

import java.util.Scanner;

public class Main{
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int[] result = new int[n*2];
        for(int i=0;i<n*2;i++){
            result[i] = in.nextInt();
        }
        int count =0;
        int length = n<<1;
        for(int i=0;i<length;){
            if(result[i]>>1 == result[i+1]>>1){
                i += 2;
                continue;
            }else{
                for(int j =i+1;j<length;j++){
                    int xuhao = result[i]>>1;
                    int temp = result[i+1];
                    if(result[j]>>1 == xuhao){
                        result[i+1] = result[j];
                        result[j] = temp;
                        count++;
                        break;
                    }
                }

            }
        }
        System.out.println(count);

    }
}