题解 | #求平均数#

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
       
        //write your code here......
        int count = 0;
        double sum = 0;
        double avg = 0;

        while (true) {
            //从键盘接收数据并存放到变量num
            int num = scan.nextInt();
            //进行判断
            if (num < 0) {
                break;
            }
            //用来统计输入数据的次数
            count++;
            //从键盘输入的数据进行求和
            sum += num;
        }
        //求平均数
        avg = sum / count;
        System.out.println(String.format("%.2f", avg));
    }
}