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);
        int sum=0,count=0,box=scan.nextInt();
        while(box>=0)
        {
           sum+=box;
           count++;
           box=scan.nextInt();
        }
        double ave=sum/1.0/count;
        System.out.printf("%.2f",ave);

    }
}