From 7af9677207d9ba2b24d662aadd8ed3ba323cfa6f Mon Sep 17 00:00:00 2001
From: Sijmen Schoon <me@sijmenschoon.nl>
Date: Thu, 6 Dec 2018 12:02:45 +0100
Subject: [PATCH] Add day 6

---
 .gitignore    |  2 ++
 Day6/Day6.py  | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++
 Day6/Day6A.py |  2 ++
 Day6/Day6B.py |  2 ++
 4 files changed, 75 insertions(+)
 create mode 100644 Day6/Day6.py
 create mode 100644 Day6/Day6A.py
 create mode 100644 Day6/Day6B.py

diff --git a/.gitignore b/.gitignore
index cd4e12a..106dd62 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,3 +7,5 @@
 *.hi
 *.o
 *.prof
+
+__pycache__
diff --git a/Day6/Day6.py b/Day6/Day6.py
new file mode 100644
index 0000000..30d085f
--- /dev/null
+++ b/Day6/Day6.py
@@ -0,0 +1,69 @@
+from pprint import pprint
+import fileinput
+import itertools
+import numpy
+
+def distance(a, b):
+    ax, ay = a
+    bx, by = b
+    return abs(ax - bx) + abs(ay - by)
+
+coordinates = []
+for line in fileinput.input():
+    x, y = line.strip().split(", ")
+    coordinates.append((int(x), int(y)))
+xs, ys = numpy.transpose(coordinates)
+
+def nearest_neighbor(x, y):
+    closest = -1
+    dist = 10000
+    for i, coord in enumerate(coordinates):
+        d = distance((x, y), coord)
+        if d < dist:
+            closest = i
+            dist = d
+        elif d == dist:
+            closest = -1
+
+    return closest
+
+def calc_farthest(padding):
+
+    xmin, xmax = min(xs) - padding, max(xs) + padding
+    ymin, ymax = min(ys) - padding, max(ys) + padding
+    w, h = xmax - xmin, ymax - ymin
+
+    grid = numpy.zeros((h + 1, w + 1), dtype=numpy.int16) - 1
+    for y, row in enumerate(grid):
+        for x in range(len(row)):
+            nn = nearest_neighbor(x + xmin, y + ymin)
+            if nn is not None:
+                grid[y, x] = nn
+
+    flat = grid.flatten()
+    flat = flat[flat >= 0]
+
+    return numpy.bincount(flat)
+
+def part1():
+    small = calc_farthest(0)
+    big = calc_farthest(10)
+    print(small[small == big].max())
+
+def part2():
+    padding = 5
+    max_dist = 10000
+
+    xmin, xmax = min(xs) - padding, max(xs) + padding
+    ymin, ymax = min(ys) - padding, max(ys) + padding
+    w, h = xmax - xmin, ymax - ymin
+
+    grid = numpy.zeros((h + 1, w + 1), dtype=numpy.int16) - 1
+    size = 0
+    for y, row in enumerate(grid):
+        for x in range(len(row)):
+            s = sum(distance((x + xmin, y + ymin), c) for c in coordinates)
+            if s < max_dist:
+                size += 1
+
+    print(size)
diff --git a/Day6/Day6A.py b/Day6/Day6A.py
new file mode 100644
index 0000000..4464e5b
--- /dev/null
+++ b/Day6/Day6A.py
@@ -0,0 +1,2 @@
+from Day6 import part1
+part1()
diff --git a/Day6/Day6B.py b/Day6/Day6B.py
new file mode 100644
index 0000000..7595a4e
--- /dev/null
+++ b/Day6/Day6B.py
@@ -0,0 +1,2 @@
+from Day6 import part2
+part2()