From 8e5b90fd35f78d55d4cb2daf9c24e8bc4b3e9a24 Mon Sep 17 00:00:00 2001
From: Ben Charlton <ben@spod.cx>
Date: Tue, 10 Dec 2019 21:35:54 +0000
Subject: [PATCH] day10

---
 10/10.py | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)
 create mode 100755 10/10.py

diff --git a/10/10.py b/10/10.py
new file mode 100755
index 0000000..d0d5abe
--- /dev/null
+++ b/10/10.py
@@ -0,0 +1,88 @@
+#!/usr/bin/env python3
+
+import sys, math
+
+grid = []
+for line in sys.stdin:
+    line = line.rstrip()
+    grid.append(line)
+
+maxcount = 0
+keepseen = {}
+keepx = 0
+keepy = 0
+
+for x in range(0, len(grid[0])):
+    for y in range(0, len(grid)):
+        
+        # skip space, as we're building on an asteroid.
+        if grid[y][x] == ".":
+            continue
+
+        seen = {}
+        count = 0
+
+        for tx in range(0, len(grid[0])):
+            for ty in range(0, len(grid)):
+            
+                # Well this is horrible, but we'll rethink later if it's too slow.
+
+                # skip space.
+                if grid[ty][tx] == ".":
+                    continue
+                
+                # Skip self
+                if tx == x and ty == y:
+                    continue
+
+                # Angle of the dangle
+                asteroid_angle = math.atan2((y-ty),(x-tx))
+                # rotate 90 degrees
+                asteroid_angle = asteroid_angle - math.pi/2
+                # wrap negative values
+                if asteroid_angle < 0:
+                    asteroid_angle = 2*math.pi + asteroid_angle
+
+                asteroid_range = math.sqrt((x-tx)**2 + (y-ty)**2)
+
+                if asteroid_angle in seen:
+                    seen[asteroid_angle][asteroid_range] = 100*tx+ty # ("%d,%d" % (tx, ty))
+                else: 
+                    t = {}
+                    t[asteroid_range] = 100*tx+ty # ("%d,%d" % (tx, ty))
+                    seen[asteroid_angle] = t
+                    count += 1
+
+        # Note the best asteroid so far. 
+        if count > maxcount:
+            maxcount = count
+            keepseen = seen
+            keepx = x
+            keepy = y
+
+# part 1 answer.
+print(maxcount)
+
+zaps = 0
+while len(keepseen) > 0:
+    for laser in sorted(keepseen.keys()):
+        zaps += 1
+        this_angle = keepseen[laser]
+        asteroids = sorted(this_angle)
+        if zaps == 200:
+            print(this_angle[asteroids[0]])
+            exit
+        #print(zaps, this_angle[asteroids[0]])
+        del this_angle[asteroids[0]]
+        if len(this_angle) == 0:
+            del keepseen[laser]
+
+
+
+
+
+
+            
+                
+
+