2024-12 python p1

1 files changed, 47 insertions, 0 deletions

diff --git a/2024/12/python/main.py b/2024/12/python/main.py
new file mode 100644
index 0000000..6faa6f1
--- /dev/null
+++ b/2024/12/python/main.py
@@ -0,0 +1,47 @@
+from fileinput import input
+
+grid = {
+    complex(idx, idy): c
+    for idy, line in enumerate(input())
+    for idx, c in enumerate(line.strip())
+}
+xmax = int(max(x.real for x in grid.keys()))
+ymax = int(max(x.imag for x in grid.keys()))
+
+seen = set()
+
+silver = 0
+
+for x in range(xmax + 1):
+    for y in range(ymax + 1):
+        c = complex(x, y)
+        if c in seen:
+            continue
+
+        # Flood fill
+        char = grid[c]
+        perimeter = area = 0
+        queue = [c]
+        while queue:
+            curr = queue.pop()
+            if curr in seen:
+                continue
+            seen.add(curr)
+
+            for dir in [1, -1, 1j, -1j]:
+                next_ = curr + dir
+                if (
+                    not (0 <= next_.real <= xmax and 0 <= next_.imag <= ymax)
+                    or grid[next_] != char
+                ):
+                    perimeter += 1
+                    continue
+
+                queue.append(next_)
+            area += 1
+        silver += perimeter * area
+
+gold = 0
+
+print("silver:", silver)
+print("gold:", gold)