[py] Port 2018_03

py/aoc/__init__.py

@@ -2,7 +2,7 @@ import sys
 import argparse
 from pathlib import Path
 
-from .y2018 import d01, d02
+from .y2018 import d01, d02, d03
 from .y2020 import d10
 from .y2021 import d14
 from .y2022 import d01, d02, d03, d04, d05, d06
@@ -10,6 +10,7 @@ from .y2022 import d01, d02, d03, d04, d05, d06
 DAYS = {
     "2018_01": y2018.d01.solve,
     "2018_02": y2018.d02.solve,
+    "2018_03": y2018.d03.solve,
     "2020_10": y2020.d10.solve,
     "2021_14": y2021.d14.solve,
     "2022_01": y2022.d01.solve,

py/aoc/y2018/d03.py

@@ -0,0 +1,57 @@
+import re
+
+CLAIM_RE = r"#(\d+) @ (\d+),(\d+): (\d+)x(\d+)"
+
+
+def load_claims(inputstr):
+    claims = {}
+    for line in inputstr.splitlines():
+        match = re.fullmatch(CLAIM_RE, line)
+        elf, x, y, w, h = match.groups()
+        elf, x, y, w, h = int(elf), int(x), int(y), int(w), int(h)
+        claims[elf] = (x, y, w, h)
+    return claims
+
+
+# PART 1
+
+
+def count_claims(claims):
+    squares = {}
+    for x, y, w, h in claims.values():
+        for dw in range(w):
+            for dh in range(h):
+                coords = (x + dw, y + dh)
+                squares[coords] = squares.get(coords, 0) + 1
+    return squares
+
+
+def find_doubles(squares):
+    return len(list(filter(lambda x: x > 1, squares.values())))
+
+
+# PART 2
+
+
+def is_intact(squares, x, y, w, h):
+    for dw in range(w):
+        for dh in range(h):
+            coords = (x + dw, y + dh)
+            if squares.get(coords, 0) > 1:
+                return False
+    return True
+
+
+def find_intact_claim(claims, squares):
+    for elf, (x, y, w, h) in claims.items():
+        if is_intact(squares, x, y, w, h):
+            return elf
+
+
+def solve(inputstr):
+    claims = load_claims(inputstr)
+    squares = count_claims(claims)
+    doubles = find_doubles(squares)
+    print(f"Part 1: {doubles}")
+    intact = find_intact_claim(claims, squares)
+    print(f"Part 2: {intact}")