[WIP] Problem 5 part 1

src/Year_2021/P5.py

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+# --- Day 5: Hydrothermal Venture ---
+
+# You come across a field of hydrothermal vents on the ocean floor! These vents
+# constantly produce large, opaque clouds, so it would be best to avoid them if
+# possible.
+
+# They tend to form in lines; the submarine helpfully produces a list of nearby
+# lines of vents (your puzzle input) for you to review. For example:
+
+# 0,9 -> 5,9
+# 8,0 -> 0,8
+# 9,4 -> 3,4
+# 2,2 -> 2,1
+# 7,0 -> 7,4
+# 6,4 -> 2,0
+# 0,9 -> 2,9
+# 3,4 -> 1,4
+# 0,0 -> 8,8
+# 5,5 -> 8,2
+
+# Each line of vents is given as a line segment in the format x1,y1 -> x2,y2
+# where x1,y1 are the coordinates of one end the line segment and x2,y2 are the
+# coordinates of the other end. These line segments include the points at both
+# ends. In other words:
+
+#     An entry like 1,1 -> 1,3 covers points 1,1, 1,2, and 1,3.
+#     An entry like 9,7 -> 7,7 covers points 9,7, 8,7, and 7,7.
+
+# For now, only consider horizontal and vertical lines: lines where either
+# x1 = x2 or y1 = y2.
+
+# So, the horizontal and vertical lines from the above list would produce the
+# following diagram:
+
+# .......1..
+# ..1....1..
+# ..1....1..
+# .......1..
+# .112111211
+# ..........
+# ..........
+# ..........
+# ..........
+# 222111....
+
+# In this diagram, the top left corner is 0,0 and the bottom right corner is
+# 9,9. Each position is shown as the number of lines which cover that point or
+# . if no line covers that point. The top-left pair of 1s, for example, comes
+# from 2,2 -> 2,1; the very bottom row is formed by the overlapping lines 0,9
+# -> 5,9 and 0,9 -> 2,9.
+
+# To avoid the most dangerous areas, you need to determine the number of points
+# where at least two lines overlap. In the above example, this is anywhere in
+# the diagram with a 2 or larger - a total of 5 points.
+
+# Consider only horizontal and vertical lines. At how many points do at least
+# two lines overlap?
+
+with open("files/P5.txt", "r") as f:
+    points = [
+        points
+        for line in f.read().strip().split("\n")
+        for points in line.split(" -> ")
+    ]
+p1 = points[::2]
+p2 = points[1::2]