题解 | #记负均正#

import java.util.*;
import java.util.stream.*;

// 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 scanner = new Scanner(System.in);
        scanner.useDelimiter("\n");
        while (scanner.hasNextInt()) {
            int num = scanner.nextInt();
            String[] next = scanner.next().split(" ");
            int[] original = new int[num];
            for (int i = 0; i < next.length; i++) {
                original[i] = Integer.parseInt(next[i]);
            }
            long count1 = Arrays.stream(original).filter(o -> o < 0).count();
            System.out.print(count1 + " ");
            OptionalDouble average = Arrays.stream(original).filter(o -> o > 0).average();
            System.out.println(average.isPresent()?String.format("%.1f", average.getAsDouble()):"0.0");
        }
    }
}