2025 day 2 and 3

adventofcode/2025/day3/day3.py

@@ -0,0 +1,48 @@
+#!/usr/bin/env python3
+import fileinput
+
+
+def part1(inp):
+    "Simple brute force solution"
+    total = 0
+    for line in inp:
+        max_jolt = 0
+        for i, a in enumerate(line):
+            for b in line[i + 1 :]:
+                max_jolt = max(max_jolt, int(a + b))
+        total += max_jolt
+    print("Part 1:", total)
+
+
+def find_max_joltage(inp):
+    """
+    Greedy algorithm: pick 12 digits from the input to form the largest
+    possible number, keeping the original order.
+    """
+    stack = []
+    for i, current in enumerate(inp):
+        while stack != [] and current > stack[-1]:
+            remaining_len = len(inp) - i
+            if len(stack) + remaining_len <= 12:
+                break
+            stack.pop()
+        stack.append(current)
+    return "".join(stack[:12])
+
+
+def part2(inp):
+    total = 0
+    for line in inp:
+        res = find_max_joltage(line)
+        total += int(res)
+    print("Part 2:", total)
+
+
+def main(inp):
+    part1(inp)
+    part2(inp)
+
+
+if __name__ == "__main__":
+    lines = [x.rstrip() for x in fileinput.input()]
+    main(lines)