Day 1

01.py

@@ -0,0 +1,33 @@
+#!/usr/bin/python
+
+from enum import IntEnum
+import math
+import operator
+
+def steps(start, delta, count):
+    sign = int(math.copysign(1, delta))
+    return [start] * count if delta == 0 else range(start + sign, start + delta + sign, sign)
+
+
+with open('01.txt', 'r') as file:
+    input = file.read()
+
+movement_lookup = {'L': -1, 'R': +1}
+direction_lookup = {0: (0, -1), 1:  (1,  0), 2: (0,  1), 3:  (-1, 0)}
+
+moves = [(movement_lookup[move[0]], int(move[1:])) for move in input.split(', ')]
+
+heading = 0
+history = [(0, 0)]
+for move in moves:
+    heading = (heading + move[0] + 4) % 4
+    delta = map(operator.mul, direction_lookup[heading], (move[1], move[1]))
+    delta_mag = max(abs(delta[0]), abs(delta[1]))
+    history += zip(steps(history[-1][0], delta[0], delta_mag),
+                   steps(history[-1][1], delta[1], delta_mag))
+
+duplicates = (x for n, x in enumerate(history) if history[:n].count(x) > 0)
+overlap = next(duplicates)
+
+print("Part 1: %s ==> %s" % (history[-1], abs(history[-1][0]) + abs(history[-1][1])))
+print("Part 2: %s ==> %s" % (overlap, abs(overlap[0]) + abs(overlap[1])))

01.txt

@@ -0,0 +1 @@
+L5, R1, L5, L1, R5, R1, R1, L4, L1, L3, R2, R4, L4, L1, L1, R2, R4, R3, L1, R4, L4, L5, L4, R4, L5, R1, R5, L2, R1, R3, L2, L4, L4, R1, L192, R5, R1, R4, L5, L4, R5, L1, L1, R48, R5, R5, L2, R4, R4, R1, R3, L1, L4, L5, R1, L4, L2, L5, R5, L2, R74, R4, L1, R188, R5, L4, L2, R5, R2, L4, R4, R3, R3, R2, R1, L3, L2, L5, L5, L2, L1, R1, R5, R4, L3, R5, L1, L3, R4, L1, L3, L2, R1, R3, R2, R5, L3, L1, L1, R5, L4, L5, R5, R2, L5, R2, L1, L5, L3, L5, L5, L1, R1, L4, L3, L1, R2, R5, L1, L3, R4, R5, L4, L1, R5, L1, R5, R5, R5, R2, R1, R2, L5, L5, L5, R4, L5, L4, L4, R5, L2, R1, R5, L1, L5, R4, L3, R4, L2, R3, R3, R3, L2, L2, L2, L1, L4, R3, L4, L2, R2, R5, L1, R2