Workers are going to enclose a new working region with a fence. For their convenience the enclosed area has to be as large as possible. They have N rectangular blocks to build the fence. The length of the ith block is Li meters. All blocks have the same height of 1 meter. The workers are not allowed to break blocks into parts. All blocks must be used to build the fence.
Input
The first line of the input file contains one integer N (3 <= N <= 100).
The following N lines describe fence blocks. Each block is represented by its length in meters (integer number, 1 <= Li <= 100).
Process to the end of file.
Output
Write to the output file one nonnegative number S  maximal possible area of the working region (in square meters). S must be written with two digits after the decimal point. If it is not possible to construct the fence from the specified blocks, write 0.00.
Sample Input
4
10
5
5
4
3
8
5
5
3
10
5
4

Could someone give some hints? Thx
How to solve the problem
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 Experienced poster
 Posts: 146
 Joined: Sat Apr 26, 2003 2:51 am
That problem is from Nothern European Regional, Nothern Subregion 2001. Take a look look at this http://neerc.ifmo.ru/subregions/northern.html

 Experienced poster
 Posts: 146
 Joined: Sat Apr 26, 2003 2:51 am
That problem is from Nothern European Regional, Nothern Subregion 2001. Take a look look at this http://neerc.ifmo.ru/subregions/northern.html
Yes, but how to binary search.Cosmin.ro wrote:Using maths you can prove that for the maximum area, the points of the poligon with the given lengths must be on a circle. Now what you have to do is find the radius length using binary serach.
I have saw the official source code, but can't imagine why to do this?
Could you give more description?