day 11 & day 12

2024/day12/day12a.py

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+with open("/home/bandeira/git.bandeira/aoc/2024/day12/input.day12", "r") as file:
+    lines = file.read().strip().split("\n")
+    n, m = len(lines), len(lines[0])
+    graph = {i + j * 1j: c for i, r in enumerate(lines) for j, c in enumerate(r)}
+    for i in range(-1, n + 1):
+        graph[i - 1 * 1j] = graph[i + m * 1j] = "#"
+    for j in range(-1, m + 1):
+        graph[-1 + j * 1j] = graph[n + j * 1j] = "#"
+    visited = set()
+
+
+def dfs(visited, node, color, dir):
+    if graph[node] != color:
+        if graph[node + dir * 1j] == color or graph[node - dir + dir * 1j] != color:
+            return 0, 1, 1
+        else:
+            return 0, 1, 0
+    if node in visited:
+        return 0, 0, 0
+    visited.add(node)
+    area, perimeter, sides = 1, 0, 0
+    for d in (1, -1, 1j, -1j):
+        a, p, s = dfs(visited, node + d, color, d)
+        area, perimeter, sides = area + a, perimeter + p, sides + s
+    return area, perimeter, sides
+
+
+ans1, ans2 = 0, 0
+for node in graph:
+    if node not in visited and graph[node] != "#":
+        area, perimeter, sides = dfs(visited, node, graph[node], 1)
+        ans1 += area * perimeter
+        ans2 += area * sides
+print(ans1, ans2)