day 23

23/a.py

@@ -0,0 +1,78 @@
+#!/usr/bin/env python3
+
+
+import re
+import pdb
+
+
+RE_LINE = re.compile(r'pos=<(-?[0-9]+),(-?[0-9]+),(-?[0-9]+)>, r=([0-9]+)')
+
+
+class Bot(object):
+    def __init__(self, x, y, z, r):
+        self.x = x
+        self.y = y
+        self.z = z
+        self.r = r
+
+    def __repr__(self):
+        return "<Bot ({},{},{}) r={}>".format(self.x, self.y, self.z, self.r)
+
+
+def getdist(bot1, x, y, z):
+    return abs(bot1.x - x) + abs(bot1.y - y) + abs(bot1.z - z)
+
+
+def main():
+    bots = []
+    with open("input.txt") as f:
+        for line in f.readlines():
+            bot = Bot(*[int(i) for i in RE_LINE.search(line).groups()])
+            bots.append(bot)
+
+
+    xs = [bot.x for bot in bots]
+    ys = [bot.y for bot in bots]
+    zs = [bot.z for bot in bots]
+
+    dist = 1
+    while dist < max(xs) - min(xs):
+        dist *= 2
+
+    while True:
+        target_count = 0
+        best = None
+        best_val = None
+        for x in range(min(xs), max(xs) + 1, dist):
+            for y in range(min(ys), max(ys) + 1, dist):
+                for z in range(min(zs), max(zs) + 1, dist):
+
+                    count = 0
+
+                    for bot in bots:
+                        calc = getdist(bot, x, y, z)
+                        if (calc - bot.r) / dist <= 0:
+                            count += 1
+                    if count > target_count:
+                        target_count = count
+                        best_val = abs(x) + abs(y) + abs(z)
+                        best = (x, y, z)
+                    elif count == target_count:
+                        if not best_val or abs(x) + abs(y) + abs(z) < best_val:
+                            best_val = abs(x) + abs(y) + abs(z)
+                            best = (x, y, z)
+
+        if dist == 1:
+            print(best_val)
+            return
+        else:
+            xs = [best[0] - dist, best[0] + dist]
+            ys = [best[1] - dist, best[1] + dist]
+            zs = [best[2] - dist, best[2] + dist]
+            dist //= 2
+
+
+
+
+if __name__ == '__main__':
+    main()