From 0d06788586cda1b1ba01524f4ba3cad147052203 Mon Sep 17 00:00:00 2001
From: Thomas Schmucker <ts@its1.de>
Date: Fri, 29 Dec 2023 12:16:59 +0100
Subject: Lösungen für Tag 24, Teil 1
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---
 src/day24.py | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 src/day24.py

(limited to 'src/day24.py')

diff --git a/src/day24.py b/src/day24.py
new file mode 100644
index 0000000..809f2d0
--- /dev/null
+++ b/src/day24.py
@@ -0,0 +1,33 @@
+class Hailstone:
+    def __init__(self, sx, sy, sz, vx, vy, vz):
+        self.sx = sx
+        self.sy = sy
+        self.sz = sz
+        self.vx = vx
+        self.vy = vy
+        self.vz = vz
+        
+        self.a = vy
+        self.b = -vx
+        self.c = vy * sx - vx * sy
+    
+    def __repr__(self):
+        return "Hailstone{" + f"a={self.a}, b={self.b}, c={self.c}" + "}"
+
+hailstones = [Hailstone(*map(int, line.replace("@", ",").split(","))) for line in open("data/day24.txt")]
+
+total = 0
+
+for i, hs1 in enumerate(hailstones):
+    for hs2 in hailstones[:i]:
+        a1, b1, c1 = hs1.a, hs1.b, hs1.c
+        a2, b2, c2 = hs2.a, hs2.b, hs2.c
+        if a1 * b2 == b1 * a2:
+            continue
+        x = (c1 * b2 - c2 * b1) / (a1 * b2 - a2 * b1)
+        y = (c2 * a1 - c1 * a2) / (a1 * b2 - a2 * b1)
+        if 200000000000000 <= x <= 400000000000000 and 200000000000000 <= y <= 400000000000000:
+            if all((x - hs.sx) * hs.vx >= 0 and (y - hs.sy) * hs.vy >= 0 for hs in (hs1, hs2)):
+                total += 1
+
+print(total)
-- 
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