From 88e2e2fdf79cfd7e2d05ed243e9bf2757e5733b0 Mon Sep 17 00:00:00 2001
From: Thibaud <thibaud.gasser@gmx.com>
Date: Mon, 4 Dec 2023 15:31:06 +0100
Subject: [PATCH] update day 3 (still wip)

---
 day3/day3.py | 48 ++++++++++++++++++++++++++----------------------
 1 file changed, 26 insertions(+), 22 deletions(-)

diff --git a/day3/day3.py b/day3/day3.py
index e220a48..a961c83 100644
--- a/day3/day3.py
+++ b/day3/day3.py
@@ -1,17 +1,18 @@
-from typing import Tuple, List, Dict, Set
+from typing import Tuple, List, Set
 from dataclasses import dataclass
-from collections import defaultdict
 
 @dataclass(frozen=True)
 class Item:
     pos: Tuple[int, int]
     symbol: str
 
+
 def browse_schema(schema):
     total_parts = 0
     buf = []
     max_row, max_col = len(schema), len(schema[0])
 
+    symbols: List[Tuple[Item, Set[Item]]] = []
     numbers: List[Item] = []
 
     for y in range(max_row):
@@ -20,11 +21,15 @@ def browse_schema(schema):
             if item.isnumeric():
                 # continue parsing full number
                 buf.append(item)
-            elif buf:
+            else:
+                neighbors = get_neighbors_of((x, y), schema)
+                symbols.append((Item((x, y), item), set(neighbors)))
+            if buf and not item.isnumeric():
                 # end of a number, do the engine part check
                 number = "".join(buf)
                 neighbors = get_neighbors((x, y), len(buf), schema)
                 start_pos = (x-len(number), y)
+                symbols.append((Item((x, y), number), get_neighbors_of((x, y), schema)))
                 numbers.append(Item(start_pos, number))
                 
                 if is_engine_part(neighbors):
@@ -33,28 +38,27 @@ def browse_schema(schema):
                 buf.clear()  # reached end of a number, clear buffer
 
     print(f"Part 1, sum of the parts numbers = {total_parts}")
+    part2(symbols, numbers)
 
-    gears: Dict[Tuple[int, int], Set[Item]] = defaultdict(set)
-    for y in range(max_row):
-        for x in range(max_col):
-            item = schema[y][x]
-            if item == "*":
-                print(f"* ({x}, {y})")
-                neighbors = [n for n in get_neighbors_of((x, y), schema) if n.symbol.isdigit()]
-                if (x, y) == (5, 8):
-                    breakpoint()
+def part2(symbols, numbers):
+    total_gears = 0
+    stars = [(s, neighbors) for s, neighbors in symbols if s.symbol == "*"]
+    for _, neighbors in stars:
+        corresponding_numbers = set()
+        digits = [n for n in neighbors if n.symbol.isdigit()]
+        for digit in digits:
+            # find full number (number.start_pos < digit.pos < number.end_pos)
+            for number in numbers:
+                if number.pos[1] - 1 <= digit.pos[1] <= number.pos[1] + 1 and number.pos[0] <= digit.pos[0] <= number.pos[0]+len(number.symbol):
+                    corresponding_numbers.add(number.symbol)
 
-                for neighbor in neighbors:
-                    neighboring_numbers = [n for n in numbers
-                        if y-1 <= n.pos[1] == y+1
-                        and n.pos[0] <= neighbor.pos[0] <= n.pos[0] + len(n.symbol)]
-                    gears[(x,y)] = gears[(x,y)].union(neighboring_numbers)
-    
-    # gears = { key: value for key, value in gears.items() if len(value) <= 2 }
+        if len(corresponding_numbers) == 2:
+            a, b = corresponding_numbers
+            total_gears += int(a) * int(b)
+            #print(f"star: {star.pos} {corresponding_numbers}")
 
-
-
-    print(f"Part 2, sum of the gear ratios = TODO")
+    print(f"Part 2, sum of gear ratios = {total_gears}")
+            
 
 
 def is_engine_part(neighbors: List[Item]) -> bool: