Score : $800$ points
There are $N$ rabbits on a number line. The rabbits are conveniently numbered $1$ through $N$. The coordinate of the initial position of rabbit $i$ is $x_i$.
The rabbits will now take exercise on the number line, by performing sets described below. A set consists of $M$ jumps. The $j$-th jump of a set is performed by rabbit $a_j$ ($2≤a_j≤N-1$). For this jump, either rabbit $a_j-1$ or rabbit $a_j+1$ is chosen with equal probability (let the chosen rabbit be rabbit $x$), then rabbit $a_j$ will jump to the symmetric point of its current position with respect to rabbit $x$.
The rabbits will perform $K$ sets in succession. For each rabbit, find the expected value of the coordinate of its eventual position after $K$ sets are performed.
The input is given from Standard Input in the following format:
$N$ $x_1$ $x_2$ $...$ $x_N$ $M$ $K$ $a_1$ $a_2$ $...$ $a_M$
Print $N$ lines. The $i$-th line should contain the expected value of the coordinate of the eventual position of rabbit $i$ after $K$ sets are performed. The output is considered correct if the absolute or relative error is at most $10^{-9}$.
3 -1 0 2 1 1 2
-1.0 1.0 2.0
Rabbit $2$ will perform the jump. If rabbit $1$ is chosen, the coordinate of the destination will be $-2$. If rabbit $3$ is chosen, the coordinate of the destination will be $4$. Thus, the expected value of the coordinate of the eventual position of rabbit $2$ is $0.5×(-2)+0.5×4=1.0$.
3 1 -1 1 2 2 2 2
1.0 -1.0 1.0
$x_i$ may not be distinct.
5 0 1 3 6 10 3 10 2 3 4
0.0 3.0 7.0 8.0 10.0