题解 | #求平均数#

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        int count = 0;
        Scanner scan = new Scanner(System.in);
        int sum = 0;
        double avg = 0;
        while (true) {
            int m = scan.nextInt();
            if (m < 0) {
                break;
            } else {
                count++;
                sum += m;
            }
        }
        if (count > 0) {  // 避免count为0时出现除以0的情况
            avg = (double) sum / count;
            System.out.println(String.format("%.2f", avg));
        } else {
            System.out.println("没有输入有效的非负整数，无法计算平均值");
        }
        scan.close();  // 记得关闭Scanner，释放资源
    }
}