题解 | #记负均正#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            int n = in.nextInt();
            int sum = 0;
            int minus = 0;
            int positive = 0;
            for(int i = 0; i < n; i++){
                int num = in.nextInt();
                if(num > 0){
                    sum+=num;
                    positive++;
                }

                if(num < 0){
                    minus++;
                }
            }
            System.out.println(minus + " " + String.format("%.1f", (positive == 0 ? (double)0 : (double)sum/positive)));
            
        }
    }
}