1.1.9.4标准输入

代码：

 1 package com.zzh;
 2 
 3 import edu.princeton.cs.algs4.StdIn;
 4 import edu.princeton.cs.algs4.StdOut;
 5 
 6 public class Average { 
 7     public static void main(String[] args) {
 8         double sum=0.0;
 9         int cnt=0;
10         while(!StdIn.isEmpty()) {
11             sum+=StdIn.readDouble();
12             cnt++;
13         }
14         double avg=sum/cnt;
15         StdOut.printf("Average is %.5f\n", avg);
16   
17     }
18 }

测试用例：

1.23456
2.34567
3.45678
4.56789

<ctrl-z>

Average is 2.90123