From 7cc13becde944812ea92496b5a8d6ac6bb6e4c58 Mon Sep 17 00:00:00 2001
From: Andrew Ekstedt <andrew.ekstedt@gmail.com>
Date: Fri, 13 Dec 2024 05:49:42 +0000
Subject: [PATCH] day 13 actually numpy is fine

---
 day13/sol.py | 59 ++++++++++++----------------------------------------
 1 file changed, 13 insertions(+), 46 deletions(-)

diff --git a/day13/sol.py b/day13/sol.py
index 7957da3..b17c89c 100644
--- a/day13/sol.py
+++ b/day13/sol.py
@@ -32,64 +32,31 @@ def solve(file):
         # Solve the linear equation:
         # k_a ax + k_b * bx = px
         # k_a ay + k_b * by = py
-        
+
         M = numpy.array([[ax, bx], [ay, by]])
         V = numpy.array([px, py])
+
         sol = numpy.linalg.solve(M,V)
         k1 = int(round(sol[0]))
         k2 = int(round(sol[1]))
+
         if k1*ax + k2*bx == px and k1*ay + k2*by == py:
-            print("yes", k1, k2)
+            #print("yes", k1, k2)
             total += 3*k1 + k2
 
-    for record in records:
-        ax, ay, bx, by, px, py = record
-
         # Part 2
-        #
-        # Can't use numpy because the values are too large for floats
-        # So here's an ad-hoc solver
+        qx = px + 10000000000000
+        qy = py + 10000000000000
 
-        px += 10000000000000
-        py += 10000000000000
+        V2 = numpy.array([qx, qy])
+        sol = numpy.linalg.solve(M,V2)
+        k1 = int(round(sol[0]))
+        k2 = int(round(sol[1]))
 
-        m00, m01 = ax, bx
-        m10, m11 = ay, by
-        v1 = px
-        v2 = py
-        
-        # subtract c*eq1 from eq2 to cancel first coefficient
-        c = F(m10,m00)
-        m10 -= c*m00
-        m11 -= c*m01
-        v2  -= c*v1
+        if k1*ax + k2*bx == qx and k1*ay + k2*by == qy:
+            #print("yes2", k1, k2)
+            total2 += 3*k1 + k2
 
-        # scale eq2
-        c = F(1,m11)
-        v2 *= c
-        m11 *= c
-
-        # subtract c*eq2 from eq1 to cancel second coefficient
-        c = F(m01,m11)
-        m01 -= c*m11
-        v1  -= c*v2
-
-        # scale eq1
-        c = F(1,m00)
-        v1  *= c
-        m00 *= c
-
-        # we now have
-        # 1*k_a + 0     = v1
-        # 0     + 1*k_b = v2
-
-        print(m00, m01, m10, m11, v1, v2)
-        if v1.denominator == 1 and v2.denominator == 1 and v1 > 0 and v2 > 0:
-            if v1*ax + v2*bx == px and v1*ay + v2*by == py:
-                print("yes2", v1, v2)
-                total2 += 3*v1 + v2
-
-        
     print(total)
     print(total2)