From b8c11565c7d41ca88091d71eb31cf3466a869975 Mon Sep 17 00:00:00 2001
From: Stefan Harmuth <pennywise@drock.de>
Date: Fri, 22 Nov 2024 09:07:41 +0100
Subject: [PATCH] day22

---
 answer_cache.json   |  10 +++
 day22.py            | 152 ++++++++++++++++++++++++++++++++++++++++++++
 inputs/input22      |   2 +
 inputs/input22_test |   2 +
 4 files changed, 166 insertions(+)
 create mode 100644 day22.py
 create mode 100644 inputs/input22
 create mode 100644 inputs/input22_test

diff --git a/answer_cache.json b/answer_cache.json
index fb99afd..a99dc72 100644
--- a/answer_cache.json
+++ b/answer_cache.json
@@ -152,5 +152,15 @@
             "wrong": [],
             "correct": 537
         }
+    },
+    "22": {
+        "1": {
+            "wrong": [],
+            "correct": 8681
+        },
+        "2": {
+            "wrong": [],
+            "correct": 1070
+        }
     }
 }
\ No newline at end of file
diff --git a/day22.py b/day22.py
new file mode 100644
index 0000000..329bf29
--- /dev/null
+++ b/day22.py
@@ -0,0 +1,152 @@
+from enum import Enum
+from heapq import heappush, heapify, heappop
+from tools.aoc import AOCDay
+from tools.coordinate import Coordinate
+from tools.grid import Grid
+from typing import Any
+
+
+class RegionType(int, Enum):
+    ROCKY = 0
+    WET = 1
+    NARROW = 2
+
+
+class Tools(int, Enum):
+    NEITHER = 0
+    TORCH = 1
+    CLIMBING_GEAR = 2
+
+
+COMMON_TOOLS = {
+    RegionType.ROCKY: {Tools.TORCH, Tools.CLIMBING_GEAR},
+    RegionType.WET: {Tools.NEITHER, Tools.CLIMBING_GEAR},
+    RegionType.NARROW: {Tools.NEITHER, Tools.TORCH},
+}
+
+
+def get_common_tool(from_region_type: RegionType, to_region_type: RegionType) -> Tools:
+    return (COMMON_TOOLS[from_region_type] & COMMON_TOOLS[to_region_type]).pop()
+
+
+class Cave(Grid):
+    def __init__(self, depth: int, target_x: int, target_y: int):
+        super().__init__()
+        self.depth = depth
+        self.target_x = target_x
+        self.target_y = target_y
+        self.set(Coordinate(0, 0), self.get_erosion_level(Coordinate(0, 0)))
+
+    def get_geologic_index(self, at: Coordinate) -> int:
+        if at.x == at.y == 0:
+            return 0
+        elif at.x == self.target_x and at.y == self.target_y:
+            return 0
+        elif at.y == 0:
+            return at.x * 16807
+        elif at.x == 0:
+            return at.y * 48271
+        else:
+            return self.get(at - Coordinate(1, 0)) * self.get(at - Coordinate(0, 1))
+
+    def get_region_type(self, at: Coordinate) -> RegionType:
+        return RegionType(self.get(at) % 3)
+
+    def get_erosion_level(self, at: Coordinate) -> int:
+        return (self.get_geologic_index(at) + self.depth) % 20183
+
+    def get(self, at: Coordinate) -> int:
+        if not self.isSet(at):
+            self.set(at, self.get_erosion_level(at))
+
+        return super().get(at)
+
+    def get_risk_level(self) -> int:
+        risk = 0
+        for x in range(0, self.target_x + 1):
+            for y in range(0, self.target_y + 1):
+                at = Coordinate(x, y)
+                risk += int(self.get_region_type(at))
+
+        return risk
+
+
+class Day(AOCDay):
+    inputs = [
+        [
+            (114, "input22_test"),
+            (8681, "input22"),
+        ],
+        [
+            (45, "input22_test"),
+            (1070, "input22"),
+        ],
+    ]
+
+    def get_params(self) -> (int, int, int):
+        """(depth, target_x, target_y)"""
+        lines = self.getInput()
+        depth = int(lines[0].split()[1])
+        target_x, target_y = map(int, lines[1].split()[1].split(","))
+        return depth, target_x, target_y
+
+    def part1(self) -> Any:
+        cave = Cave(*self.get_params())
+        return cave.get_risk_level()
+
+    def part2(self) -> Any:
+        params = self.get_params()
+        target = Coordinate(*params[1:])
+        cave = Cave(*params)
+        queue = [(0, 0, Tools.TORCH, Coordinate(0, 0))]
+        heapify(queue)
+        visited = set()
+
+        target_dist, target_tool = None, None
+        while len(queue) > 0:
+            _, current_dist, current_tool, at = heappop(queue)
+            if (at, current_tool) in visited:
+                continue
+
+            visited.add((at, current_tool))
+
+            if at == target:
+                target_dist = current_dist
+                target_tool = current_tool
+                break
+
+            for next in at.getNeighbours(includeDiagonal=False, minX=0, minY=0):
+                region_type_at = cave.get_region_type(at)
+                region_type_next = cave.get_region_type(next)
+                if region_type_at == region_type_next:
+                    common_tool = current_tool
+                else:
+                    common_tool = get_common_tool(region_type_at, region_type_next)
+
+                if common_tool == current_tool:
+                    heappush(
+                        queue, (next.getDistanceTo(target) + current_dist + 1, current_dist + 1, common_tool, next)
+                    )
+                else:
+                    heappush(
+                        queue, (next.getDistanceTo(target) + current_dist + 7, current_dist + 8, common_tool, next)
+                    )
+
+        if target_tool != Tools.TORCH:
+            target_dist += 7
+            while queue:
+                _, current_dist, current_tool, at = heappop(queue)
+                if at != target or current_dist >= target_dist:
+                    continue
+
+                if current_tool == Tools.TORCH:
+                    target_dist = current_dist
+                elif current_dist + 7 < target_dist:
+                    target_dist = current_dist + 7
+
+        return target_dist
+
+
+if __name__ == "__main__":
+    day = Day(2018, 22)
+    day.run(verbose=True)
diff --git a/inputs/input22 b/inputs/input22
new file mode 100644
index 0000000..d341d05
--- /dev/null
+++ b/inputs/input22
@@ -0,0 +1,2 @@
+depth: 5616
+target: 10,785
diff --git a/inputs/input22_test b/inputs/input22_test
new file mode 100644
index 0000000..058dd01
--- /dev/null
+++ b/inputs/input22_test
@@ -0,0 +1,2 @@
+depth: 510
+target: 10,10
\ No newline at end of file