Budget

Budget

Avin’s company has many ongoing projects with different budgets. His company records the budgets using numbers rounded to 3 digits after the decimal place. However, the company is updating the system and all budgets will be rounded to 2 digits after the decimal place. For example, 1.004 will be rounded down
to 1.00 while 1.995 will be rounded up to 2.00. Avin wants to know the difference of the total budget caused by the update.

Input

The first line contains an integer n (1 ≤ n ≤ 1, 000). The second line contains n decimals, and the i-th decimal ai (0 ≤ ai ≤ 1e18) represents the budget of the i -th project. All decimals are rounded to 3 digits.

Output

Print the difference rounded to 3 digits..

Sample Input

1
1.001
1
0.999
2
1.001 0.999

Sample Output

-0.001
0.001
0.000

思路：看小数点后第三位的数，如果小于5就减去该数乘以0.001，如果大于等于5就加上（10减该数乘以0.001）。

 

#include<bits/stdc++.h>

using namespace std;
int main()
{
	int n;
	cin >> n;
	double ans = 0;
	while(n --){
	    string a;
	    cin >> a;
	    int l = a.length() ;
	    for(int i = 0;i < l;i ++){
		   if(a[i] == '.'){
			   if(a[i+3] - '0' <= 4) ans -= (a[i+3]-'0')*0.001;
			   else ans += (10 - (a[i+3]-'0'))*0.001; 
		   }
	    }  
	}
	printf("%.3lf\n",ans) ;
	return 0;
}