def path_len(r):
G = nx.Graph()
points = sorted(list(sphere_points(r)))
print len(points)
bands = [[]]
curr_band = -r
for p1 in points:
if p1[0] == curr_band:
bands[-1].append(p1)
else:
curr_band = p1[0]
bands.append([p1])
l = len(bands)
look_ahead=4
tol = 1./(l-1)
for i in xrange(l-1):
for j in xrange(look_ahead):
if i==l-1-j:
break
for p1,p2 in product(bands[i],bands[i+1+j]):
d = sphere_dist(p1,p2,r)**2
if d < tol or j==1:
G.add_edge(p1,p2,weight=d)
print len(G.edges())
# print [b[0][0] for b in bands]
# for i,p1 in enumerate(points):
# for j,p2 in enumerate(points):
# if not i == j:
# G.add_edge(p1,p2,weight=sphere_dist(p1,p2,r)**2)
# print nx.shortest_path(G,(r,0,0),(-r,0,0),weight="weight")
return nx.shortest_path_length(G,(r,0,0),(-r,0,0),weight="weight")
def path_len_old(r):
G = nx.Graph()
points = sorted(list(sphere_points(r)))
# print len(points)
for i,p1 in enumerate(points):
for j,p2 in enumerate(points):
if not i == j:
G.add_edge(p1,p2,weight=sphere_dist(p1,p2,r)**2)
# print nx.shortest_path(G,(r,0,0),(-r,0,0),weight="weight")
return nx.shortest_path_length(G,(r,0,0),(-r,0,0),weight="weight")
from proj_euler import sphere_points
n = 10 ** 10
s = 0
for p in sphere_points(n):
s += abs(p[0]) + abs(p[1]) + abs(p[2])
print s