|Author:||А. Жихарева||Time limit:||2 sec|
|Input file:||Standard input||Memory limit:||512 Mb|
|Output file:||Standard output|
There are N points on a circle, represented by numbers ai, where ai — direction from center to point i, measured in 1/100th parts of degree.
Your program must choose a set of pairs of points so that:
First line of input contains integer N.
Second line contains N integers ai — directions from center to points, measured in 1/100th parts of degree.
Output must contain two integers S and M, where S — largest total arc length, M — number of selected pairs.
Next, output must contain M pairs of integers — pairs of point indices corresponding to the ends of each arc. Indices start with 1. The order of points in pair may be arbitrary.
If there are several optimal solutions, output any of them.
2 ≤ N ≤ 5000, 0 ≤ ai < 36000
|No.||Standard input||Standard output|