NC235156. Circle
描述
输入描述
The first line contains a single positive integer denoting the number of test cases.
For each test case, the first line contains two integers and separated by a single space denoting the number of vertices of the convex hull and the radius. If , the convex hull contains only point. If , the convex hull is a line segment.
Each of the following lines contains two integers separated by a single space denoting a vertex at . It is guaranteed that no two vertices coincide and no three vertices are collinear. Vertices are listed in counter-clockwise order.
It is guaranteed that the sum of over all test cases does not exceed .
输出描述
Output a single decimal indicating the answer. Your answer will be considered correct if the absolute or relative error is no more than .
示例1
输入:
3 4 1 0 0 1 0 1 1 0 1 4 1 0 0 1 1 0 2 -1 1 4 100 0 0 1 0 1 1 0 1
输出:
0.315146743628 0 31016.928202570849