1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
|
import sys
input = lambda: sys.stdin.readline().rstrip()
from itertools import pairwise
def II(base=10):
return int(input(),base)
def LI():
return list(map(int,input()))
def LII():
return list(map(int,input().split()))
def LFI():
return list(map(float,input().split()))
def dot(u,v):
return u[0]*v[0]+u[1]*v[1]
def cross(u,v):
return u[0]*v[1]-u[1]*v[0]
n,m = LII()
A = [LFI() for _ in range(n)]
cmp = lambda x: (x>=0)-(x<=0)
for _ in range(m):
x0, y0, x1, y1 = LFI()
u = [x1-x0,y1-y0]
delta = (u[0]**2+u[1]**2)**0.5
B = []
for x,y in A:
v = [x-x0,y-y0]
B.append([dot(u,v),cross(u,v)])
C = []
for u,v in zip(B,B[1:]+B[:1]):
if cmp(u[1])!=cmp(v[1]):
C.append([cross(u,v)/(v[1]-u[1]),cmp(v[1])-cmp(u[1])])
C.sort()
res,s = 0,0
for a,b in pairwise(C):
s += a[1]
if s:
res += b[0]-a[0]
print(res/delta)
|