Day 23 ⭐⭐

Author: JesperDramsch

2023/README.md

@@ -168,3 +168,7 @@ Absolute ugly brute force. Best not to run this...
 ### 2023-12-23
 
 -   Forgot an enumerate
+-   Had to figure out how to search all paths possible...
+-   Using networkx, but turns out it doesn't have an easy way to find the "longest path", all set to the shortest one.
+-   Mixed up the check `has_nodes` and `has_edges`, which gave an error. I should sleep probably...
+-   Takes a bit to run part 2

2023/day23.py

@@ -1,13 +1,19 @@
 from day import Day
 from aocd import submit
 from heapq import heappush, heappop
+import networkx as nx
+import time
+import sys
+
+sys.setrecursionlimit(10000)
 
 
 class Clouds:
     def __init__(self, data):
         self.parse(data)
         self.max = len(self.grid)
         self.visited = set()
+        self.graph = nx.Graph()
 
     def __repr__(self):
         return f"Clouds({self.start}, {self.end})"
@@ -27,7 +33,8 @@ def parse(self, data):
 
     def get_neighbors(self, pos):
         for i in [1j, -1j, 1, -1]:
-            yield pos - i
+            if pos + i in self.grid:
+                yield pos + i
 
     def longest_hike(self):
         dummy = 0
@@ -60,8 +67,43 @@ def longest_hike(self):
                     heappush(queue, (dist - 1, dummy := dummy + 1, neighbor, visited.copy()))
         return -max_dist
 
+    def create_graph(self, dist=0, last_node=None, pos=None, last_pos=None):
+        if last_node is None:
+            last_node = self.start
+        if pos is None:
+            pos = self.start
+
+        # End of the grid
+        if pos == self.end:
+            self.graph.add_edge(last_node, pos, weight=dist)
+            return
+        # Already visited
+        if self.graph.has_edge(last_node, pos):
+            return
+
+        neighbors = list(self.get_neighbors(pos))
+        # Adding a node to the graph when it's a junction
+        if len(neighbors) > 2:
+            self.graph.add_edge(last_node, pos, weight=dist)
+            last_node = pos
+            dist = 0
+        # Moving further in the grid
+        for neighbor in neighbors:
+            if neighbor in self.grid and neighbor != last_pos:
+                self.create_graph(dist + 1, last_node, neighbor, pos)
+
+    def unconstrained_longest(self):
+        self.create_graph()
+        print(self.graph)
+        # Find longest Path in graph
+        max_dist = 0
+        for path in nx.all_simple_paths(G=self.graph, source=self.start, target=self.end):
+            max_dist = max(max_dist, nx.path_weight(self.graph, path, weight="weight"))
+        return max_dist
+
     def print(self):
         for i in range(1 + int(max(x.real for x in self.grid))):
+            print(i, end=" ")
             for ii in range(1 + int(max(x.imag for x in self.grid))):
                 if i + ii * 1j in self.visited:
                     print("O", end="")
@@ -77,49 +119,23 @@ def print(self):
 def main(day, part=1):
     clouds = Clouds(day.data)
     print(clouds)
-    clouds.longest_hike()
-    clouds.print()
     if part == 1:
-        return clouds.longest_hike()
+        x = clouds.longest_hike()
+        clouds.print()
+        return x
     if part == 2:
-        pass
+        return clouds.unconstrained_longest()
 
 
 if __name__ == "__main__":
     day = Day(23)
     day.download()
 
     day.load()
-    #     data = """#.#####################
-    # #.......#########...###
-    # #######.#########.#.###
-    # ###.....#.>.>.###.#.###
-    # ###v#####.#v#.###.#.###
-    # ###.>...#.#.#.....#...#
-    # ###v###.#.#.#########.#
-    # ###...#.#.#.......#...#
-    # #####.#.#.#######.#.###
-    # #.....#.#.#.......#...#
-    # #.#####.#.#.#########v#
-    # #.#...#...#...###...>.#
-    # #.#.#v#######v###.###v#
-    # #...#.>.#...>.>.#.###.#
-    # #####v#.#.###v#.#.###.#
-    # #.....#...#...#.#.#...#
-    # #.#########.###.#.#.###
-    # #...###...#...#...#.###
-    # ###.###.#.###v#####v###
-    # #...#...#.#.>.>.#.>.###
-    # #.###.###.#.###.#.#v###
-    # #.....###...###...#...#
-    # #####################.#"""
-
-    #     day.load(data)
     p1 = main(day)
     print(p1)
     submit(p1, part="a", day=23, year=2023)
 
-    # day.load()
-    # p2 = main(day, part=2)
-    # print(p2)
-    # submit(p2, part="b", day=23, year=2023)
+    p2 = main(day, part=2)
+    print(p2)
+    submit(p2, part="b", day=23, year=2023)

2023/tests/test_day23.py

@@ -59,4 +59,4 @@ def test_example_p2(example):
 
 
 def test_part2(day):
-    assert main(day, part=2) == False
+    assert main(day, part=2) == 6490

README.md

@@ -60,15 +60,15 @@ Get acquainted with Advent of Code and solve some of the puzzles in Python.
 
 ### [2023](./2023/)
 
-|        | 1st | 2nd | 3rd | 4th              | 5th              | 6th              | 7th              | 8th              | 9th              | 10th             | 11th             | 12th             | 13th             |
-| ------ | --- | --- | --- | ---------------- | ---------------- | ---------------- | ---------------- | ---------------- | ---------------- | ---------------- | ---------------- | ---------------- | ---------------- |
-| Part 1 | ⭐  | ⭐  | ⭐  | ⭐ | ⭐ | ⭐ | ⭐ | ⭐ | ⭐ | ⭐ | ⭐ | ⭐ | ⭐ |
-| Part 2 | ⭐  | ⭐  | ⭐  | ⭐ | ⭐ | ⭐ | ⭐ | ⭐ | ⭐ | ⭐ | ⭐ | ⭐ | ⭐ |
-
-|        | 14th             | 15th             | 16th             | 17th             | 18th             | 19th             | 20th             | 21st             | 22nd             | 23rd             | 24th             | 25th             |
-| ------ | ---------------- | ---------------- | ---------------- | ---------------- | ---------------- | ---------------- | ---------------- | ---------------- | ---------------- | ---------------- | ---------------- | ---------------- |
-| Part 1 | ⭐ | ⭐ | ⭐ | ⭐ | ⭐ | ⭐ | ⭐ | <!--2023.21.1--> | ⭐ | ⭐ | <!--2023.24.1--> | <!--2023.25.1--> |
-| Part 2 | ⭐ | ⭐ | ⭐ | ⭐ | ⭐ | ⭐ | ⭐ | <!--2023.21.2--> | ⭐ | <!--2023.23.2--> | <!--2023.24.2--> | <!--2023.25.2--> |
+|        | 1st | 2nd | 3rd | 4th | 5th | 6th | 7th | 8th | 9th | 10th | 11th | 12th | 13th |
+| ------ | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---- | ---- | ---- | ---- |
+| Part 1 | ⭐  | ⭐  | ⭐  | ⭐  | ⭐  | ⭐  | ⭐  | ⭐  | ⭐  | ⭐   | ⭐   | ⭐   | ⭐   |
+| Part 2 | ⭐  | ⭐  | ⭐  | ⭐  | ⭐  | ⭐  | ⭐  | ⭐  | ⭐  | ⭐   | ⭐   | ⭐   | ⭐   |
+
+|        | 14th | 15th | 16th | 17th | 18th | 19th | 20th | 21st | 22nd | 23rd | 24th             | 25th             |
+| ------ | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---------------- | ---------------- |
+| Part 1 | ⭐   | ⭐   | ⭐   | ⭐   | ⭐   | ⭐   | ⭐   | ⭐   | ⭐   | ⭐   | <!--2023.24.1--> | <!--2023.25.1--> |
+| Part 2 | ⭐   | ⭐   | ⭐   | ⭐   | ⭐   | ⭐   | ⭐   | ⭐   | ⭐   | ⭐   | <!--2023.24.2--> | <!--2023.25.2--> |
 
 ### [2022](./2022/)