Financial Management



描述

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.

输入

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.

输出

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.

样例输入

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

样例输出

1581.42

解题思路：

本题主要是读懂题，难度也只是在于题目的翻译，首先应该明白，本题是求平均数。我一开始想把这十二个数放到数组里进行计算，可是后来想这样比较繁琐，而且占内存，就直接，用循环将十二组数据相加，再求取平均值。

其代码如下：

#include<stdio.h>
int main()
{
	int i;
	double a,sum=0;
	for(i=0;i<12;i++)
	{
		scanf("%lf",&a);
		sum+=a;
	}
	printf("%.2f\n",sum/12);
	return 0;
}