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 n = 0;
        int sum = 0;
        float i = 0.0f;
        double average = 0.0;
        //输出格式为：System.out.println(String.format("%.2f",avg));
        while(scan.hasNextInt()){
            n = scan.nextInt();
            if (n < 0){
                break;
            }else{
                i++;
                sum += n;
            }
        }
        average = sum / i;
        System.out.println(String.format("%.2f",average));

    }
}