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 a = in.nextInt();
        //     int b = in.nextInt();
        //     System.out.println(a + b);
        // }
        int n = in.nextInt();
        int sum = 0;
        int countp = 0;
        int countm = 0;
        while (in.hasNextInt()) {
            int a = in.nextInt();
            if (a < 0) {
                countm++;
            } else if (a > 0) {
                sum += a;
                countp++;
            }
        }
        System.out.print(countm + " ");
        if (sum == 0) {
            System.out.print("0.0");
        } else {
            System.out.printf("%.1f", (float)sum / countp);
        }
    }
}