Solution to problem 3 part 1 in Python

src/Year_2018/P3.py

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+# --- Day 3: No Matter How You Slice It ---
+
+# The Elves managed to locate the chimney-squeeze prototype fabric for Santa's
+# suit (thanks to someone who helpfully wrote its box IDs on the wall of the
+# warehouse in the middle of the night). Unfortunately, anomalies are still
+# affecting them - nobody can even agree on how to cut the fabric.
+
+# The whole piece of fabric they're working on is a very large square - at
+# least 1000 inches on each side.
+
+# Each Elf has made a claim about which area of fabric would be ideal for
+# Santa's suit. All claims have an ID and consist of a single rectangle with
+# edges parallel to the edges of the fabric. Each claim's rectangle is defined
+# as follows:
+
+#     The number of inches between the left edge of the fabric and the left
+# edge of the rectangle.
+#     The number of inches between the top edge of the fabric and the top edge
+# of the rectangle.
+#     The width of the rectangle in inches.
+#     The height of the rectangle in inches.
+
+# A claim like #123 @ 3,2: 5x4 means that claim ID 123 specifies a rectangle 3
+# inches from the left edge, 2 inches from the top edge, 5 inches wide, and 4
+# inches tall. Visually, it claims the square inches of fabric represented by
+# # (and ignores the square inches of fabric represented by .) in the diagram
+# below:
+
+# ...........
+# ...........
+# ...#####...
+# ...#####...
+# ...#####...
+# ...#####...
+# ...........
+# ...........
+# ...........
+
+# The problem is that many of the claims overlap, causing two or more claims to
+# cover part of the same areas. For example, consider the following claims:
+
+# #1 @ 1,3: 4x4
+# #2 @ 3,1: 4x4
+# #3 @ 5,5: 2x2
+
+# Visually, these claim the following areas:
+
+# ........
+# ...2222.
+# ...2222.
+# .11XX22.
+# .11XX22.
+# .111133.
+# .111133.
+# ........
+
+# The four square inches marked with X are claimed by both 1 and 2. (Claim 3,
+# while adjacent to the others, does not overlap either of them.)
+
+# If the Elves all proceed with their own plans, none of them will have enough
+# fabric. How many square inches of fabric are within two or more claims?
+
+import numpy as np
+
+with open("files/P3.txt") as f:
+    claims = [line for line in f.read().strip().split("\n")]
+
+
+def part_1() -> None:
+    grid = np.zeros((1000, 1000), dtype=int)
+
+    for claim in claims:
+        claim_id, _, orig, size = claim.split()
+        left, top = orig[:-1].split(",")
+        width, height = size.split("x")
+        for row in range(int(top), int(top) + int(height)):
+            for col in range(int(left), int(left) + int(width)):
+                grid[row][col] += 1
+
+    print(
+        f"There are {np.count_nonzero(grid >= 2)} square inches within two "
+        f"or more claims"
+    )
+
+
+if __name__ == "__main__":
+    part_1()