day 2

2025/02/solution.py

@@ -0,0 +1,57 @@
+#!/usr/bin/env python3
+import sys
+import pathlib
+
+def read_input():
+    path = pathlib.Path(sys.argv[1]) if len(sys.argv) > 1 else pathlib.Path("input.txt")
+    return path.read_text().replace(",", "\n").rstrip("\n")
+
+def parse(data):
+    return data.splitlines()
+
+def part1(data):
+    sum=0
+    for ids in data:
+        buf = ids.split("-")
+        start = int(buf[0])
+        end = int(buf[1])
+
+        for i in range(start, end + 1):
+            s = str(i)
+            length = len(s)
+            if length % 2 == 0:
+                mid = len(s) // 2
+                first = s[:mid]
+                rest = s[mid:]
+                if first == rest:
+                    sum += i
+    return sum
+
+def part2(data):
+    sum = 0
+    for ids in data:
+        start, end = map(int, ids.split("-"))
+        for i in range(start, end + 1):
+            numstr = str(i)
+            invalid = False
+            for c in range(1, len(numstr)//2 + 1):
+                if len(numstr) % c != 0:
+                    continue
+                chunks = [numstr[j:j+c] for j in range(0, len(numstr), c)]
+                if all(chunks[0] == chunks[k] for k in range(1, len(chunks))):
+                    invalid = True
+                    break
+            if invalid:
+                sum += i
+    return sum
+
+def main():
+    raw = read_input()
+    data = parse(raw)
+    r1 = part1(data)
+    r2 = part2(data)
+    print(r1)
+    print(r2)
+
+if __name__ == "__main__":
+    main()