19、Financial Management

Description

Larry graduated this year and finally has a job. He's making a lot of money, but somehow never seems to have enough. Larry has decided that he needs to grab hold of his financial portfolio and solve his financing problems. The first step is to figure out what's been going on with his money. Larry has his bank account statements and wants to see how much money he has. Help Larry by writing a program to take his closing balance from each of the past twelve months and calculate his average account balance.

Input

The input will be twelve lines. Each line will contain the closing balance of his bank account for a particular month. Each number will be positive and displayed to the penny. No dollar sign will be included.

Output

The output will be a single number, the average (mean) of the closing balances for the twelve months. It will be rounded to the nearest penny, preceded immediately by a dollar sign, and followed by the end-of-line. There will be no other spaces or characters in the output.

Sample Input

100.00
489.12
12454.12
1234.10
823.05
109.20
5.27
1542.25
839.18
83.99
1295.01
1.75

Sample Output

$1581.42

 

解题思路：这道题就是一道求均值的题，唯一的亮点为对输出格式的控制。用

DecimalFormat decimalFormat=new DecimalFormat("#.00");

这样的方式实现题目的格式要求。

代码示例：

import java.util.*;
import java.text.*;
public class Main {
     public static void main(String[] args) {
          Scanner scanner =new Scanner(System.in);
          double sum=0;
          double temp;
          for(int i=0;i<12;i++){
              temp=scanner.nextDouble();
              sum+=temp;
          }
          System.out.println("$"+formatDouble(sum/12));
     }
     public static String formatDouble(double b){
          DecimalFormat decimalFormat=new DecimalFormat("#.00");
          return decimalFormat.format(b);
     }
}

做题感悟：学会了Java中对小数格式的控制。