From c9f98d2a1c293d403b7ee43fffc5a3a1bc26e310 Mon Sep 17 00:00:00 2001 From: Ilya Zverev Date: Thu, 2 Nov 2017 11:05:03 +0300 Subject: [PATCH] Better find_segment --- subway_structure.py | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/subway_structure.py b/subway_structure.py index d6899bc..a941546 100644 --- a/subway_structure.py +++ b/subway_structure.py @@ -98,14 +98,26 @@ def project_on_line(p, line): def find_segment(p, line, start_vertex=0): """Returns index of a segment and a position inside it.""" + EPS = 1e-9 for seg in range(start_vertex, len(line)-1): if is_near(p, line[seg]): return seg, 0 - px = (p[0] - line[seg][0]) / (line[seg+1][0] - line[seg][0]) - if 0 <= px <= 1: - py = (p[1] - line[seg][1]) / (line[seg+1][1] - line[seg][1]) - if px-1e-10 <= py <= px+1e-10: - return seg, px + if line[seg][0] == line[seg+1][0]: + if not (p[0]-EPS <= line[seg][0] <= p[0]+EPS): + continue + px = None + else: + px = (p[0] - line[seg][0]) / (line[seg+1][0] - line[seg][0]) + if px is None or (0 <= px <= 1): + if line[seg][1] == line[seg+1][1]: + if not (p[1]-EPS <= line[seg][1] <= p[1]+EPS): + continue + py = None + else: + py = (p[1] - line[seg][1]) / (line[seg+1][1] - line[seg][1]) + if py is None or (0 <= py <= 1): + if py is None or px is None or (px-EPS <= py <= px+EPS): + return seg, px or py return None, None