From 19bd3221b34e7fb6b389c61b54897e8290287149 Mon Sep 17 00:00:00 2001
From: Dmitry Fedotov <dafedotov@gmail.com>
Date: Fri, 27 Dec 2024 22:08:19 +0300
Subject: [PATCH] add day8 part 2

---
 day8/code.py         | 89 +++++++++++++++++++++++++++++++-------------
 day8/input_test2.txt | 10 +++++
 day8/task.txt        |  2 +
 3 files changed, 75 insertions(+), 26 deletions(-)
 create mode 100644 day8/input_test2.txt

diff --git a/day8/code.py b/day8/code.py
index 2a668c1..0da3f25 100644
--- a/day8/code.py
+++ b/day8/code.py
@@ -2,63 +2,100 @@ import sys
 sys.path.append('../aoclib')
 
 from aoclib import Input
+import sys
+
+sys.setrecursionlimit(10**6)
 
 def find_pairs(field):
-    '''suboptimal (shitty) code'''
     pairs = set()
     for y in range(len(field)):
         for x in range(len(field[0])):
             if field[y][x] == '.':
                 continue
-            for y2 in range(len(field)):
+            for y2 in range(y, len(field)):
                 for x2 in range(len(field[0])):
                     if x == x2 and y == y2:
                         continue
                     if field[y][x] == field[y2][x2]:
                         # this is a pair
-                        pairs.add((x, y, x2, y2))
+                        pairs.add(((x, y), (x2, y2)))
     return pairs
 
-def find_antinodes(pair, field):
-    x, y, x2, y2 = pair
-    x_diff = abs(x - x2)
-    y_diff = abs(y - y2)
+def find_antinodes(pair: tuple[tuple[int]], field):
+    p1, p2 = pair
+    x_diff = p2[0] - p1[0]
+    y_diff = p2[1] - p1[1]
 
-    one, two = None, None
-    if x2 >= x and y2 >= y:
-        one = (y-y_diff, x-x_diff)
-        two = (y2+y_diff, x2+x_diff)
-    elif x2 >= x and y2 < y:
-        one = (y+y_diff, x-x_diff)
-        two = (y2-y_diff, x2+x_diff)
+    one, two = (p1[0] - x_diff, p1[1] - y_diff), (p2[0] + x_diff, p2[1] + y_diff)
 
-    antinodes = []
-    if one and not out_of_bounds(one, field):
-        antinodes.append(one)
-    if two and not out_of_bounds(two, field):
-        antinodes.append(two)
-
-    return antinodes
+    nodes = []
+    if out_of_bounds(one, field):
+        one = None
+    if out_of_bounds(two, field):
+        two = None
+        
+    return one, two
 
+            
 def out_of_bounds(c, field):
     return c[0] < 0 or c[1] < 0 or c[0] >= len(field[0]) or c[1] >= len(field)
 
+
 def solve1(field: list):
     pairs = find_pairs(field)
-    print(pairs)
     antinodes = set()
     for p in pairs:
-        for anode in find_antinodes(p, field):
-            antinodes.add(anode)
+        one, two = find_antinodes(p, field)
+        if one:
+            antinodes.add(one)
+        if two:
+            antinodes.add(two)
+
+    return len(antinodes)
+
+
+def solve2(field: list):
+    pairs = find_pairs(field)
+    antinodes = set()
+    for p in pairs:
+        p1, p2 = p
+        antinodes.add(p1)
+        antinodes.add(p2)
+        
+        one, two = find_antinodes(p, field)
+        run = True
+        while run:
+            _one, _two = None, None
+            if one:
+                antinodes.add(one)
+                _one, _ = find_antinodes((one, p1), field)
+            if two:
+                antinodes.add(two)
+                _, _two = find_antinodes((p2, two), field)
+
+            if not _one and not _two:
+                run = False
+                continue
+
+            if _one:
+                p1 = one
+                one = _one
+                
+            if _two:
+                p2 = two
+                two = _two                
+
     return len(antinodes)
 
 
 if __name__ == '__main__':
-    #field = Input('input_test.txt').lines_as_lists()
+    #field = Input('input_test2.txt').lines_as_lists()
     field = Input('input.txt').lines_as_lists()
 
+    # print(find_pairs(field))
+
     #part 1
     print('part 1:', solve1(field))
 
     #part 2
-    print('part 2:', '')
+    print('part 2:', solve2(field))
diff --git a/day8/input_test2.txt b/day8/input_test2.txt
new file mode 100644
index 0000000..d12dbde
--- /dev/null
+++ b/day8/input_test2.txt
@@ -0,0 +1,10 @@
+T....#....
+...T......
+.T....#...
+.........#
+..#.......
+..........
+...#......
+..........
+....#.....
+..........
diff --git a/day8/task.txt b/day8/task.txt
index 638dd68..64493e7 100644
--- a/day8/task.txt
+++ b/day8/task.txt
@@ -115,4 +115,6 @@ The original example now has 34 antinodes, including the antinodes that appear o
 
 Calculate the impact of the signal using this updated model. How many unique locations within the bounds of the map contain an antinode?
 
+Your puzzle answer was 1249.
 
+Both parts of this puzzle are complete! They provide two gold stars: **