2018 day6 (slow)

2018/day6/day6.py

@@ -1,9 +1,55 @@
+from collections import defaultdict, namedtuple
+
+
+Point = namedtuple('Point', ['x', 'y'])
+
+
 def dist(a, b):
     "manhattan distance"
     return abs(a.x - b.x) + abs(a.y - b.y)
 
+
+def iter_grid(bounds):
+    min_, max_ = bounds
+    for x in range(min_.x, max_.x + 1):
+        for y in range(min_.y, max_.y + 1):
+            yield Point(x, y)
+
+
+def is_edge(p, bounds):
+    start, end = bounds
+    return p.x == start.x or p.x == end.x or p.y == start.y or p.y == end.y
+
+
 def main(inp):
-    pass
+    grid = [Point(*map(int, l.split(", "))) for l in inp]
+    bounds = (Point(min(p.x for p in grid), min(p.y for p in grid)),
+              Point(max(p.x for p in grid), max(p.y for p in grid)))
+
+    areas = defaultdict(int)
+    infinite_regions = set()
+    for p in iter_grid(bounds):
+        # find dist to every point of grid
+        distances = sorted((dist(p2, p), i) for i, p2 in enumerate(grid))
+        # equally far from two or more coordinates, don't count
+        if distances[0][0] == distances[1][0]:
+            continue
+        _, index = distances[0]
+        areas[index] += 1
+        if is_edge(p, bounds):
+            infinite_regions.add(index)
+
+    # remove all infinite regions by index
+    for i in infinite_regions:
+        del areas[i]
+    print("Part 1: ", max(areas.values()))
+    
+    count = 0
+    for cur in iter_grid(bounds):
+        s = sum(dist(cur, p) for p in grid)
+        if s < 10_000:
+            count += 1
+    print("Part 2: ", count)
 
 
 if __name__ == "__main__":