RR has a board with 2 rows and � co

RR has a board with 2 rows and � columns. RR will use 2� numbers from 1 to 2� to fill in this
board. The locations of these numbers on the board are random. More precisely, for each
number from 1 to 2�, RR will put it in one random, empty position on the board.
Let array � be the first row of the board and array � be the second row of the board. Note that
both arrays will have exactly � numbers. Let � = |�) − �)| )+,…. . Your task is to calculate the
expected value of F.
Input
The input starts with the number of test - � (� ≤ 1000). Then � tests follow. Each test contains a
single integer �. (1 ≤ � ≤ 103)
Output
For each test in the input, print the answer with exactly 2 digits after decimal place.

Results (English) 3:

RR有板2行�柱。从1到2的RR将使用�2�号码填在这板。在董事会上这些数字的位置是随机的。更确切地说，为每个从1到2�号，RR会把它放在一个随机的，棋盘上的空位置。让阵列�董事会和阵列�第一行董事会排第二。请注意，数组必须完全�数。让�= |�）−�）|）+，的…，你的任务是计算F期望值输入输入开始和一些测试�（�≤1000）。然后�测试遵循。每个测试包含一个单一的整数�。（1≤�≤103）输出对于输入中的每个测试，在小数点后精确的2位数字打印答案。