atcoder#ABC197D. [ABC197D] Opposite

[ABC197D] Opposite

Score : 400400 points

Problem Statement

On a two-dimensional coordinate plane where the x\mathrm{x} axis points to the right and the y\mathrm{y} axis points up, we have a regular NN-gon with NN vertices p0,p1,p2,,pN1p_0, p_1, p_2, \dots, p_{N - 1}. Here, NN is guaranteed to be even, and the vertices p0,p1,p2,,pN1p_0, p_1, p_2, \dots, p_{N - 1} are in counter-clockwise order. Let (xi,yi)(x_i, y_i) denotes the coordinates of pip_i. Given x0x_0, y0y_0, xN2x_{\frac{N}{2}}, and yN2y_{\frac{N}{2}}, find x1x_1 and y1y_1.

Constraints

  • 4N1004 \le N \le 100
  • NN is even.
  • 0x0,y01000 \le x_0, y_0 \le 100
  • 0xN2,yN21000 \le x_{\frac{N}{2}}, y_{\frac{N}{2}} \le 100
  • (x0,y0)(xN2,yN2)(x_0, y_0) \neq (x_{\frac{N}{2}}, y_{\frac{N}{2}})
  • All values in input are integers.

Input

Input is given from Standard Input in the following format:

NN

x0x_0 y0y_0

xN2x_{\frac{N}{2}} yN2y_{\frac{N}{2}}

Output

Print x1x_1 and y1y_1 in this order, with a space in between. Your output is considered correct when, for each value printed, the absolute or relative error from our answer is at most 10510^{-5}.

4
1 1
2 2
2.00000000000 1.00000000000

We are given p0=(1,1)p_0 = (1, 1) and p2=(2,2)p_2 = (2, 2). The fact that p0p_0, p1p_1, p2p_2, and p3p_3 form a square and they are in counter-clockwise order uniquely determines the coordinates of the other vertices, as follows:

  • p1=(2,1)p_1 = (2, 1)
  • p3=(1,2)p_3 = (1, 2)
6
5 3
7 4
5.93301270189 2.38397459622