Solve 2025 day 1 and 2

2025/d01.py

@@ -1,5 +1,22 @@
 from lib import get_data
 
-data = get_data(__file__)
-print(data)
+NUM = 100
 
+data = get_data(__file__)
+
+pos = 50
+r1, r2 = 0, 0
+for line in data.splitlines():
+    d = line[0]
+    n = int(line[1:])
+    dir = 1 if d == "R" else -1
+
+    for _ in range(n):
+        pos = (pos + dir) % NUM
+        if pos == 0:
+            r2 += 1
+    if pos == 0:
+        r1 += 1
+
+print(r1)
+print(r2)

2025/d02.py

@@ -0,0 +1,34 @@
+from lib import get_data
+
+
+data = get_data(__file__)
+
+def is_invalid(xs: str) -> bool:
+    for seq_len in range(1, len(xs) // 2 + 1):
+        if xs[:seq_len] == xs[seq_len:]:
+            return True
+    return False
+
+def is_invalid2(xs: str) -> bool:
+    for seq_len in range(1, len(xs)):
+        if len(xs) % seq_len != 0:
+            continue
+        for repeat in range(len(xs) // seq_len):
+            i = seq_len * repeat
+            if xs[:seq_len] != xs[i:i + seq_len]:
+                break
+        else:
+            return True
+    return False
+
+r1, r2 = 0, 0
+for id_range in data.split(","):
+    lo, up = list(map(int, id_range.split("-")))
+    for id in range(lo, up + 1):
+        if is_invalid(str(id)):
+            r1 += id
+        if is_invalid2(str(id)):
+            r2 += id
+
+print(r1)
+print(r2)

README.md

@@ -7,7 +7,13 @@ Solutions and utility script for Advent of Code challenges in Python.
 Only twelve problems and no leaderboard this year. That means life will be less
 stressful and this will actually be more fun. Thank you Eric Wastl and let's go!
 
-- Day  1:
+- Day 1: Maybe the hardest day 1 part 2 ever for me? I struggled to calculate
+  the number of ticks on 0 directly and ended up just iterating over all the
+  ticks naively. Maybe I should revisit this.
+- Day 2: The simple direct approach with iterating over all the IDs in the
+  ranges just worked okay. Not pretty but acceptable.
+- Day 3:
+
 
 ## AoC 2024