From f96335f8398f4f889ffb4bcc4d920fc76235cdc2 Mon Sep 17 00:00:00 2001
From: Tabledevil <tabledevil@gmail.com>
Date: Fri, 13 Dec 2024 13:22:14 +0100
Subject: [PATCH] Add 13 Part 2 Solution

---
 13/13.ipynb | 81 ++++++++++++++++++-----------------------------------
 1 file changed, 27 insertions(+), 54 deletions(-)

diff --git a/13/13.ipynb b/13/13.ipynb
index ce9733f..7ac84a9 100644
--- a/13/13.ipynb
+++ b/13/13.ipynb
@@ -2,41 +2,44 @@
  "cells": [
   {
    "cell_type": "code",
-   "execution_count": 7,
+   "execution_count": 161,
    "metadata": {},
    "outputs": [],
    "source": [
     "import numpy as np\n",
     "import re\n",
     "\n",
-    "def readfile(infilename='testinput',offset=0):\n",
-    "    pattern= re.compile(r'''[XY][+=](\\d+)''')   #Pattern to Extract Values\n",
-    "    A=np.zeros((2,2),dtype=int)                 #Empty 2x2 Matrix\n",
-    "    B=None                                      #Placeholder for PrizePosition\n",
+    "pattern= re.compile(r'''[XY][+=](\\d+)''')   #Pattern to Extract Values\n",
     "\n",
+    "def readfile(infilename='testinput',offset=0):\n",
     "    with open(infilename,'r') as infile:\n",
     "        for idx,line in enumerate(infile.readlines()):\n",
     "            line = line.strip()\n",
     "            # on empty line yield result and reset\n",
     "            if line =='':\n",
-    "                if B is not None:\n",
-    "                    solution = np.linalg.solve(A.astype(int),B.astype(int))\n",
-    "                    # remove non integer Solutions\n",
-    "                    solution = solution.astype(int) if np.allclose(solution, np.round(solution)) else None\n",
-    "                    yield A,B,solution\n",
-    "                A=np.zeros((2,2))\n",
-    "                B=None\n",
     "                continue\n",
     "            # grep X/Y Values from Line\n",
     "            matches = pattern.findall(line)\n",
     "            if \"Button A\" in line:  #A Button Presses are X in my equation > first column of A\n",
+    "                A=np.zeros((2,2),dtype=int)\n",
     "                A[:,0]=matches\n",
     "            if \"Button B\" in line:  #B Button Presses are Y in my equation > second column of A\n",
     "                A[:,1]=matches\n",
-    "            if \"Prize:\" in line:\n",
-    "                B=np.array(matches,dtype=int)+[offset,offset] #offset added for part 2"
+    "            if \"Prize:\" in line:    #Prize Position is the result of solving the equation > B\n",
+    "                B=np.array(matches,dtype=int)+np.array([offset,offset]) #offset added for part 2\n",
+    "                solution = np.linalg.solve(A.astype(int),B.astype(int),)\n",
+    "                # remove non integer Solutions by rounding and checking validity of solution\n",
+    "                reverse = np.dot(A,np.round(solution))\n",
+    "                validation = np.all(np.equal(reverse,B.astype(int)))\n",
+    "                solution = solution.round().astype(int) if validation else None\n",
+    "                yield solution\n"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": []
+  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -46,22 +49,22 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 8,
+   "execution_count": 162,
    "metadata": {},
    "outputs": [
     {
      "data": {
       "text/plain": [
-       "28714"
+       "np.int64(28753)"
       ]
      },
-     "execution_count": 8,
+     "execution_count": 162,
      "metadata": {},
      "output_type": "execute_result"
     }
    ],
    "source": [
-    "sum(a*3 + b for a,b in [x[2] for x in readfile('input') if x[2] is not None ])"
+    "sum((np.sum(x*[3,1]) for x in readfile('input') if x is not None ))"
    ]
   },
   {
@@ -73,58 +76,28 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 225,
+   "execution_count": 163,
    "metadata": {},
    "outputs": [
     {
      "data": {
       "text/plain": [
-       "[(array([[69., 27.],\n",
-       "         [23., 71.]]),\n",
-       "  array([10000000018641, 10000000010279]),\n",
-       "  array([102851800151, 107526881786]))]"
+       "np.int64(102718967795500)"
       ]
      },
-     "execution_count": 225,
+     "execution_count": 163,
      "metadata": {},
      "output_type": "execute_result"
     }
    ],
    "source": [
-    "[x for x in readfile(offset=10000000000000) if x[2] is not None ]\n"
+    "sum((np.sum(x*[3,1]) for x in readfile('input',offset=10000000000000) if x is not None ))"
    ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 226,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "text/plain": [
-       "416082282239"
-      ]
-     },
-     "execution_count": 226,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "sum(a*3 + b for a,b in [x[2] for x in readfile(offset=10000000000000) if x[2] is not None ])\n"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
-   "source": []
   }
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 3",
+   "display_name": "advent",
    "language": "python",
    "name": "python3"
   },
@@ -138,7 +111,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.8.10"
+   "version": "3.13.0"
   }
  },
  "nbformat": 4,