Solution to problem 3 part 1 in Python

src/Year_2019/P3.py

@@ -57,23 +57,28 @@
 # What is the Manhattan distance from the central port to the closest
 # intersection?
 
-with open("files/test.txt") as f:
+from math import inf
+from typing import List
+
+from sympy import Segment
+
+with open("files/P3.txt") as f:
     wire_a, wire_b = [path.split(",") for path in f.read().strip().split()]
 
 
-def get_final_point(init, direction, length):
+def get_final_point(init: List[int], direction: str, length: int) -> List[int]:
-    if direction == "U":
+    if direction == "R":
         init[0] += length
-    elif direction == "D":
-        init[0] -= length
-    elif direction == "R":
-        init[1] += length
     elif direction == "L":
+        init[0] -= length
+    elif direction == "U":
+        init[1] += length
+    elif direction == "D":
         init[1] -= length
     return init
 
 
-def get_path(wire):
+def get_path(wire: List[str]) -> List[List[int]]:
     init = [0, 0]
     path = []
     for step in wire:
@@ -82,57 +87,29 @@ def get_path(wire):
         # make a copy of the final point to avoid reference to same object
         path.append(final_point.copy())
         init = final_point
-    # add starting point
+    return path
-    return [[0, 0]] + path
 
 
-# print(len(get_path(wire_a)))
-# print(len(get_path(wire_b)))
-
-
-def line(p1, p2):
-    A = p1[1] - p2[1]
-    B = p2[0] - p1[0]
-    C = p1[0] * p2[1] - p2[0] * p1[1]
-    return A, B, -C
-
-
-def intersection(L1, L2):
-    D = L1[0] * L2[1] - L1[1] * L2[0]
-    Dx = L1[2] * L2[1] - L1[1] * L2[2]
-    Dy = L1[0] * L2[2] - L1[2] * L2[0]
-    if D != 0:
-        x = Dx // D
-        y = Dy // D
-        return x, y
-    else:
-        return False
-
-
-# L1 = line([10,1003], [476,1003])
-# L2 = line([250, 500], [250, 1200])
-
-# R = intersection(L1, L2)
-# if R:
-#     print(f"Intersection detected at {R}")
-# else:
-#     print("No single intersection point detected")
-
 path_a = get_path(wire_a)
-print(path_a[:5])
 path_b = get_path(wire_b)
-print(path_b[:5])
 
 
-for p1_a, p2_a, p1_b, p2_b in zip(
+def part_1() -> None:
-    path_a[:-1], path_a[1:], path_b[:-1], path_b[1:]
+    closest = inf
-):
+    for p1, p2 in zip(path_a[:-1], path_a[1:]):
-    # for idx_b, (p1_b, p2_b) in enumerate(zip(path_b[:-1], path_b[1:])):
+        s1 = Segment(p1, p2)
-    line_a = line(p2_a, p1_a)
+        for p3, p4 in zip(path_b[:-1], path_b[1:]):
-    print(line_a)
+            s2 = Segment(p3, p4)
-    line_b = line(p2_b, p1_b)
+            intersect = s1.intersection(s2)
-    print(line_b)
+            if intersect:
-    R = intersection(line_a, line_b)
+                manhattan_distance = abs(intersect[0][0]) + abs(
-    if R:
+                    intersect[0][1]
-        print(p1_a, p2_a, p1_b, p2_b)
+                )
-        break
+                if manhattan_distance < closest:
+                    closest = manhattan_distance
+
+    print(f"The manhattan distance to the closest intersection is {closest}")
+
+
+if __name__ == "__main__":
+    part_1()