1 files changed, 41 insertions, 0 deletions
diff --git a/2024/10/python/main.py b/2024/10/python/main.py
new file mode 100644
index 0000000..4e85b49
--- /dev/null
+++ b/2024/10/python/main.py
@@ -0,0 +1,41 @@
+from fileinput import input
+
+grid = [[int(c) for c in line.strip()] for line in input()]
+
+starts = {
+    (idx, idy) for idy, line in enumerate(grid) for idx, n in enumerate(line) if n == 0
+}
+
+# print(*grid, sep="\n")
+# print(starts)
+
+
+def score_trailhead(start, gold):
+    score = 0
+    q = [start]
+    seen = set()
+    while q:
+        x, y = q.pop()
+        seen.add((x, y))
+
+        h = grid[y][x]
+        if h == 9:
+            score += 1
+            continue
+        for dx, dy in [(0, 1), (0, -1), (1, 0), (-1, 0)]:
+            nx, ny = x + dx, y + dy
+            if ((nx, ny) in seen and not gold) or not (
+                0 <= nx < len(grid) and 0 <= ny < len(grid[0])
+            ):
+                continue
+
+            if grid[ny][nx] == h + 1:
+                q.append((nx, ny))
+    return score
+
+
+silver = sum(score_trailhead(start, False) for start in starts)
+gold = sum(score_trailhead(start, True) for start in starts)
+
+print("silver:", silver)
+print("gold:", gold)