From: Pat Thoyts <pat.thoyts@gmail.com>
Date: Sun, 3 Dec 2023 09:52:05 +0000 (+0000)
Subject: day3: completed part 2
X-Git-Url: http://privyetmir.co.uk/gitweb?a=commitdiff_plain;h=4f584776ee4351a1a51cb4196f3f4221d8600103;p=aoc2023.git

day3: completed part 2
---

diff --git a/day3/data/test_input b/day3/data/test_input
index 6537f8b..b20187f 100644
--- a/day3/data/test_input
+++ b/day3/data/test_input
@@ -8,4 +8,3 @@
 ......755.
 ...$.*....
 .664.598..
-
diff --git a/day3/run.py b/day3/run.py
index fb2d64e..e53b320 100755
--- a/day3/run.py
+++ b/day3/run.py
@@ -13,7 +13,17 @@ def main(args=None):
 
     with open(options.filename, 'r') as input:
         schematic = Schematic.fromstream(input)
-        print(f"part1: {sum(schematic.parts)}")
+        partnos = [p.number for p in schematic.parts]
+        print(f"part1: {sum(partnos)}")
+
+        collection = []
+        for gear in schematic.gears:
+            if len(schematic.gears[gear]) > 1:
+                collection.append([part.number for part in schematic.gears[gear]])
+
+        result = sum([(g[0] * g[1]) for g in collection])
+        print(f"part2: {result}")
+
     return 0
 
 
diff --git a/day3/schematic.py b/day3/schematic.py
index ef060b6..143d885 100644
--- a/day3/schematic.py
+++ b/day3/schematic.py
@@ -1,11 +1,46 @@
+from dataclasses import dataclass
 from typing import List
 
 
+@dataclass
+class Position:
+    row: int = 0
+    col: int = 0
+
+
+@dataclass
+class Symbol:
+    symbol: str
+    pos: Position
+
+    @property
+    def symid(self):
+        return self.pos.row * 1000 + self.pos.col
+
+
+@dataclass
+class Part:
+    number: int
+    symbols: List[Symbol]
+
+    def __repr__(self) -> str:
+        return f"Part(number='{self.number}',symbols='{self.symbols}')"
+
+    @property
+    def is_valid(self):
+        return bool(self.symbols)
+    
+    @property
+    def is_gear(self):
+        return [sym for sym in self.symbols if sym.symbol == '*']
+
+
 class Schematic:
     def __init__(self, rows: List[str]):
         self.rows = rows
         self.span = len(rows[0])
         self.parts = []
+        self.gears = {}
         self.debug = True
         self.update()
 
@@ -18,7 +53,7 @@ class Schematic:
                 c = self.rows[row][col]
                 if c.isdigit():
                     part['digits'].append(c)
-                    part['symbols'].append(self.get_neighbours(row, col))
+                    part['symbols'] += self.get_neighbours(row, col)
                 else:
                     if part['digits']:
                         self._complete_part(part)
@@ -26,24 +61,31 @@ class Schematic:
             if part['digits']:
                 self._complete_part(part)
                 part = {'digits': [], 'symbols':[]}
+        # get gears
+        for part in self.parts:
+            if part.is_gear:
+                symid = part.is_gear[0].symid
+                self.gears.setdefault(symid, [])
+                self.gears[symid].append(part)
+        #print(self.gears)
 
-    def _complete_part(self, part:dict):
-        value = int(''.join(part['digits']))
-        valid = bool(''.join(part['symbols']))
+    def _complete_part(self, data:dict):
+        value = int(''.join(data['digits']))
+        part = Part(value, data['symbols'])
         if self.debug:
-            print(value, valid, ''.join(part['symbols']))
-        if valid:
-            self.parts.append(value)
+            print(part.number, part.is_valid, part.symbols)
+        if part.is_valid:
+            self.parts.append(part)
 
-    def get_neighbours(self, row: int, col: int) -> bool:
-        result = ''
+    def get_neighbours(self, row: int, col: int) -> List[Position]:
+        result = []
         for r in [row - 1, row, row + 1]:
             if r >= 0 and r < len(self.rows):
                 for c in [col - 1, col, col + 1]:
                     if c >= 0 and c < self.span:
                         t = self.rows[r][c]
                         if not (t.isdigit() or t == '.'):
-                            result = result + t
+                            result.append(Symbol(t, Position(r, c)))
         return result
 
     @staticmethod
diff --git a/day3/test_schematic.py b/day3/test_schematic.py
index f07335f..17a320a 100644
--- a/day3/test_schematic.py
+++ b/day3/test_schematic.py
@@ -1,6 +1,4 @@
 import unittest
-import os
-import sys
 from io import StringIO
 from schematic import Schematic
 
@@ -9,17 +7,50 @@ class TestPart1(unittest.TestCase):
     def test_schematic_sum(self):
         with open('data/test_input') as input:
             schematic = Schematic.fromstream(input)
+            partnos = [p.number for p in schematic.parts]
             self.assertSequenceEqual(
                 [467, 35, 633, 617, 592, 755, 664, 598],
-                schematic.parts)
-            self.assertEqual(4361, sum(schematic.parts))
+                partnos)
+            self.assertEqual(4361, sum(partnos))
 
     def test_schematic_from_file2(self):
         with open('data/test_input2') as input:
             schematic = Schematic.fromstream(input)
             self.assertSequenceEqual(
                 [467, 35, 633, 617, 592, 755, 664, 598],
-                schematic.parts)
+                [p.number for p in schematic.parts])
+
+
+class TestPart2(unittest.TestCase):
+    def test_is_gear(self):
+        stream = StringIO("111...\n..*...\n..222.\n")
+        schematic = Schematic.fromstream(stream)
+        part = schematic.parts[0]
+        self.assertTrue(part.is_gear)
+
+    def test_gears(self):
+        stream = StringIO("111...\n..*...\n..222.\n")
+        schematic = Schematic.fromstream(stream)
+        print(schematic.gears)
+        self.assertEqual(1, len(schematic.gears))
+        self.assertEqual(2, len(schematic.gears[1002]))
+        self.assertEqual([111, 222], [part.number for part in schematic.gears[1002]])
+
+    def test_gear_ratio(self):
+        with open('data/test_input') as input:
+            schematic = Schematic.fromstream(input)
+            collection = []
+            for gear in schematic.gears:
+                if len(schematic.gears[gear]) > 1:
+                    collection.append([part.number for part in schematic.gears[gear]])
+
+            self.assertEqual(
+                [[467, 35], [755, 598]],
+                collection)
+            self.assertEqual(
+                467835,
+                sum([(g[0] * g[1]) for g in collection]))
+
 
 if __name__ == '__main__':
     unittest.main()