y=x

y=x+1

(n,n)

(n-1,n+1)

如果非法径 过 红线，则在第一个过红线的点开始，做原路径关于红线的
对称路径，原路径最终到达(n,n),则新路径最终节点是(n-1,n+1)

A = Intersect(xAxis, yAxis)
B = Point(xAxis)
f = Segment(A, B)
C = (3, 4)
g = Segment(C, B)
D = (8, 4)
h = Segment(C, D)
E = (8, 8)
i = Segment(E, D)
F = (10.212296189346672, 10.174154591863031)
j = Segment(A, F)
G = Point(yAxis)
H = (10, 11)
k = Segment(G, H)
I = Intersect(g, k)
J = Point(j)
K = (4, 9)
M = (7, 9)
L = (3, 9)
N = Intersect(g, h)
O = Intersect(g, k)
P = Point(j)
l = Segment(O, P)
Q = Intersect(h, k)
p = Segment(P, Q)
S = Intersect(h, k)
R = (4, 9)
T = (3, 9)
U = Intersect(g, h)
m = Segment(T, U)
q = Segment(T, M)