aoc

commit 424ffd61c58eb127f9a657a854737e2d82368217
parent 10caeb18b9c224c8b42ca724e956dba35807ec2c
Author: Sebastiano Tronto <sebastiano@tronto.net>
Date:   Fri,  5 Dec 2025 06:39:31 +0100

Day 5 2025

Diffstat:
M
2025/05/a.py
 | 
15
+++++++++++++--
A
2025/05/b.py
 | 
26
++++++++++++++++++++++++++
M
2025/README.md
 | 
8
++++++++
M
README.md
 | 
2
+-

4 files changed, 48 insertions(+), 3 deletions(-)
diff --git a/2025/05/a.py b/2025/05/a.py
@@ -1,6 +1,17 @@
 import fileinput
 
+rang = True
+ranges = []
+s = 0
 with fileinput.input() as lines:
 	for line in lines:
-		...
-
+		if line == '\n':
+			rang = False
+		elif rang:
+			i = line.find('-')
+			ranges.append((int(line[:i]), int(line[i+1:-1])))
+		else:
+			x = int(line[:-1])
+			if any(x >= r[0] and x <= r[1] for r in ranges):
+				s += 1
+print(s)
diff --git a/2025/05/b.py b/2025/05/b.py
@@ -0,0 +1,26 @@
+import fileinput
+
+def overlap(r1, r2):
+	return min(r1[1], r2[1]) >= max(r1[0], r2[0])
+
+def fuse(r1, r2):
+	return (min(r1[0], r2[0]), max(r1[1], r2[1]))
+
+ranges = []
+with fileinput.input() as lines:
+	for line in lines:
+		if line == '\n':
+			break
+		i = line.find('-')
+		ranges.append((int(line[:i]), int(line[i+1:-1])))
+
+s = set()
+for r in ranges:
+	c = r
+	for rr in list(s):
+		if overlap(c, rr):
+			c = fuse(c, rr)
+			s.remove(rr)
+	s.add(c)
+
+print(sum(r[1] - r[0] + 1 for r in s))
diff --git a/2025/README.md b/2025/README.md
@@ -11,6 +11,7 @@ Example
 
 ```
 Day   -Part 1-   -Part 2-
+  5   00:04:39   00:22:19
   4   00:25:36   00:27:49
   3   00:05:02   00:16:09
   2   00:10:36   00:11:55
@@ -61,3 +62,10 @@ out of bounds.
 
 For part 2 I decided to quickly code the dumb "repeat part 1 until no
 rolls are removed" strategy and it worked.
+
+### Day 5: Cafeteria
+
+Part 2 required a little bit of thinking to handle overlaps correctly
+- at first I wrote a solution that did not handle overlaps, then one
+that can only handle single overlaps, and finally one that works in
+every case. My final solution is quite straightforward.
diff --git a/README.md b/README.md
@@ -14,4 +14,4 @@ See `year/README.md` for instructions on how to run my code.
 |2022|  50 | Rust   | Done in 2025 to learn Rust |
 |2023|  50 | C      | All solved by December 25, 2023 |
 |2024|  50 | C++    | Each solved within 24h |
-|2025|  8  | Python | Work in progress... |
+|2025|  10 | Python | Work in progress... |