Problem1004

/**
 * 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
 */
package acm;

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Problem1004 {
	public static void main(String[] args) {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		double sum = 0.00;
		//计算总额
		for (int i = 0; i < 12; i++) {
			try {
				sum += Double.parseDouble(br.readLine());
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		//计算平均数
		double avg = sum/12;
		//四舍五入到两位小数
		if(avg%0.01>0.0045){
			avg+=0.01;
		}
		//乘以100将头两位小数纳入，再除以100将结果精确到两位小数
		avg*=100;
		avg-=(avg%1);
		avg/=100;
		System.out.println("$"+avg);
	}
}

题目：有个小子想算算自己银行账户一年每个月平均能剩多少钱
里面的精确到小数后两位可把我的懒脑累惨了，后来才发现原来*100再/100就能完成这个工作