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......
    double avg = 0;
    double sum = 0;
    int count = 0;
    
    while(true){
       Double num = scan.nextDouble(); 
       if(num < 0)break;
         count++;
         sum = sum + num;
    }
       avg = sum/count;
    System.out.println(String.format("%.2f",avg));
}

}