There are n magical circles on a plane. They are centered at (x1, y1),(x2, y2), . . . ,(xn, yn), respectively. In the beginning, the radius of each circle is 0, and the radii of all magical circles will grow at the same rate. When an magical circle touches another, then it stops growing. Write a program to calculate the total area of all magical circles at the end of growing.
输入描述:
The first line contains an integer n to indicate the number of magical circles. The i-th of thefollowing n lines contains two space-separated integers xi and yi indicating that the i-th magicalcircle is centered at (xi , yi).
输出描述:
Output the total area of the circles.
备注:
• 2 ≤ n ≤ 2000
• xi, yi ∈ [−109, 109] for i ∈ {1, 2, . . . , n}.
• All (xi , yi)’s are disinct points.
• A relative error of 10−6 is acceptable.