From fc80c822a2eca53a138047713fc25ebfd51e3ce0 Mon Sep 17 00:00:00 2001
From: Stefan Harmuth <pennywise@drock.de>
Date: Sat, 21 Dec 2024 10:35:46 +0100
Subject: [PATCH] day21 - slightly cheated

---
 day21.py                | 195 ++++++++++++++++++++++++++++++++++++++++
 inputs/input21          |   5 ++
 inputs/input21_jonathan |   5 ++
 inputs/input21_test     |   5 ++
 inputs/input21_test2    |   1 +
 5 files changed, 211 insertions(+)
 create mode 100644 day21.py
 create mode 100644 inputs/input21
 create mode 100644 inputs/input21_jonathan
 create mode 100644 inputs/input21_test
 create mode 100644 inputs/input21_test2

diff --git a/day21.py b/day21.py
new file mode 100644
index 0000000..c5d8eec
--- /dev/null
+++ b/day21.py
@@ -0,0 +1,195 @@
+from tools.aoc import AOCDay
+from typing import Any
+
+ARROW_PATHS = {
+    ("A", "<"): "v<<",
+    ("A", ">"): "v",
+    ("A", "^"): "<",
+    ("A", "v"): "<v",
+    ("^", "<"): "v<",
+    ("^", ">"): "v>",
+    ("^", "A"): ">",
+    ("<", "A"): ">>^",
+    ("<", "^"): ">^",
+    ("<", "v"): ">",
+    ("v", "A"): "^>",
+    ("v", "<"): "<",
+    ("v", ">"): ">",
+    (">", "A"): "^",
+    (">", "^"): "<^",
+    (">", "v"): "<",
+}
+
+KEYPAD_PATHS = {
+    ("A", "0"): "<",
+    ("A", "1"): "^<<",
+    ("A", "2"): "<^",
+    ("A", "3"): "^",
+    ("A", "4"): "^^<<",
+    ("A", "5"): "<^^",
+    ("A", "6"): "^^",
+    ("A", "7"): "^^^<<",
+    ("A", "8"): "<^^^",
+    ("A", "9"): "^^^",
+    ("0", "A"): ">",
+    ("0", "1"): "^<",
+    ("0", "2"): "^",
+    ("0", "3"): "^>",
+    ("0", "4"): "^^<",
+    ("0", "5"): "^^",
+    ("0", "6"): ">^^",
+    ("0", "7"): "^^^<",
+    ("0", "8"): "^^^",
+    ("0", "9"): "^^^>",
+    ("1", "A"): ">>v",
+    ("1", "0"): ">v",
+    ("1", "2"): ">",
+    ("1", "3"): ">>",
+    ("1", "4"): "^",
+    ("1", "5"): "^>",
+    ("1", "6"): ">>^",
+    ("1", "7"): "^^",
+    ("1", "8"): ">^^",
+    ("1", "9"): ">>^^",
+    ("2", "A"): "v>",
+    ("2", "0"): "v",
+    ("2", "1"): "<",
+    ("2", "3"): ">",
+    ("2", "4"): "<^",
+    ("2", "5"): "^",
+    ("2", "6"): "^>",
+    ("2", "7"): "<^^",
+    ("2", "8"): "^^",
+    ("2", "9"): "^^>",
+    ("3", "A"): "v",
+    ("3", "0"): "<v",
+    ("3", "1"): "<<",
+    ("3", "2"): "<",
+    ("3", "4"): "<<^",
+    ("3", "5"): "<^",
+    ("3", "6"): "^",
+    ("3", "7"): "<<^^",
+    ("3", "8"): "<^^",
+    ("3", "9"): "^^",
+    ("4", "A"): ">>vv",
+    ("4", "0"): ">vv",
+    ("4", "1"): "v",
+    ("4", "2"): "v>",
+    ("4", "3"): "v>>",
+    ("4", "5"): ">",
+    ("4", "6"): ">>",
+    ("4", "7"): "^",
+    ("4", "8"): "^>",
+    ("4", "9"): "^>>",
+    ("5", "A"): "vv>",
+    ("5", "0"): "vv",
+    ("5", "1"): "<v",
+    ("5", "2"): "v",
+    ("5", "3"): "v>",
+    ("5", "4"): "<",
+    ("5", "6"): ">",
+    ("5", "7"): "<^",
+    ("5", "8"): "^",
+    ("5", "9"): "^>",
+    ("6", "A"): "vv",
+    ("6", "0"): "<vv",
+    ("6", "1"): "<<v",
+    ("6", "2"): "<v",
+    ("6", "3"): "v",
+    ("6", "4"): "<<",
+    ("6", "5"): "<",
+    ("6", "7"): "<<^",
+    ("6", "8"): "<^",
+    ("6", "9"): "^",
+    ("7", "A"): ">>vvv",
+    ("7", "0"): ">vvv",
+    ("7", "1"): "vv",
+    ("7", "2"): "vv>",
+    ("7", "3"): "vv>>",
+    ("7", "4"): "v",
+    ("7", "5"): "v>",
+    ("7", "6"): "v>>",
+    ("7", "8"): ">",
+    ("7", "9"): ">>",
+    ("8", "A"): "vvv>",
+    ("8", "0"): "vvv",
+    ("8", "1"): "<vv",
+    ("8", "2"): "vv",
+    ("8", "3"): "vv>",
+    ("8", "4"): "<v",
+    ("8", "5"): "v",
+    ("8", "6"): "v>",
+    ("8", "7"): "<",
+    ("8", "9"): ">",
+    ("9", "A"): "vvv",
+    ("9", "0"): "<vvv",
+    ("9", "1"): "<<vv",
+    ("9", "2"): "<vv",
+    ("9", "3"): "vv",
+    ("9", "4"): "<<v",
+    ("9", "5"): "<v",
+    ("9", "6"): "v",
+    ("9", "7"): "<<",
+    ("9", "8"): "<",
+}
+
+
+def get_arrow_path(code: str, paths: dict[tuple[str, str], str]) -> str:
+    cur_pos = "A"
+    path = ""
+    for c in code:
+        if cur_pos != c:
+            path += paths[(cur_pos, c)]
+
+        path += "A"
+        cur_pos = c
+
+    return path
+
+
+class Day(AOCDay):
+    inputs = [
+        [
+            (126384, "input21_test"),
+            (224326, "input21_jonathan"),
+            (163920, "input21"),
+        ],
+        [
+            (279638326609472, "input21_jonathan"),
+            (204040805018350, "input21"),
+        ],
+    ]
+
+    def get_path_len(self, code: str, num_pads: int = 2) -> int:
+        if num_pads == 0:
+            return len(code)
+
+        if (code, num_pads) in self.DP:
+            return self.DP[code, num_pads]
+
+        path = get_arrow_path(code, ARROW_PATHS)
+        p_len = 0
+        for sub_path in path.split("A")[:-1]:
+            p_len += self.get_path_len(sub_path + "A", num_pads - 1)
+
+        self.DP[code, num_pads] = p_len
+        return self.DP[code, num_pads]
+
+    def get_full_len(self, num_keypads: int = 2) -> int:
+        ans = 0
+        for code in self.getInput():
+            key_pad_path = get_arrow_path(code, KEYPAD_PATHS)
+            ans += self.get_path_len(key_pad_path, num_keypads) * int(code[:-1])
+
+        return ans
+
+    def part1(self) -> Any:
+        return self.get_full_len()
+
+    def part2(self) -> Any:
+        return self.get_full_len(25)
+
+
+if __name__ == "__main__":
+    day = Day(2024, 21)
+    day.run(verbose=True)
diff --git a/inputs/input21 b/inputs/input21
new file mode 100644
index 0000000..90601d6
--- /dev/null
+++ b/inputs/input21
@@ -0,0 +1,5 @@
+671A
+083A
+582A
+638A
+341A
diff --git a/inputs/input21_jonathan b/inputs/input21_jonathan
new file mode 100644
index 0000000..60ab29c
--- /dev/null
+++ b/inputs/input21_jonathan
@@ -0,0 +1,5 @@
+208A
+540A
+685A
+879A
+826A
\ No newline at end of file
diff --git a/inputs/input21_test b/inputs/input21_test
new file mode 100644
index 0000000..dd73dfd
--- /dev/null
+++ b/inputs/input21_test
@@ -0,0 +1,5 @@
+029A
+980A
+179A
+456A
+379A
\ No newline at end of file
diff --git a/inputs/input21_test2 b/inputs/input21_test2
new file mode 100644
index 0000000..66657da
--- /dev/null
+++ b/inputs/input21_test2
@@ -0,0 +1 @@
+3A
\ No newline at end of file