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;
        int count =0;
        while (true){
            int num = scan.nextInt();
            if(num<0){
                break;
            }
            sum=sum+num;
            count++;


        }
        double average =(double)sum/count;
        System.out.printf("%.2f", average);


    }
}