From 4742910afd4464a000a153bc78344079436dc3a5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Anders=20Engl=C3=B6f=20Ytterstr=C3=B6m?= <yttan@fastmail.se>
Date: Wed, 25 Oct 2023 23:26:51 +0200
Subject: [PATCH] Solve 2015:10 "Elves Look, Elves Say"

---
 2015-python/solutions/day_10.py  | 39 ++++++++++++++++++++++++++++++++
 2015-python/tests/test_day_10.py | 31 +++++++++++++++++++++++++
 2 files changed, 70 insertions(+)
 create mode 100644 2015-python/solutions/day_10.py
 create mode 100644 2015-python/tests/test_day_10.py

diff --git a/2015-python/solutions/day_10.py b/2015-python/solutions/day_10.py
new file mode 100644
index 0000000..fedf388
--- /dev/null
+++ b/2015-python/solutions/day_10.py
@@ -0,0 +1,39 @@
+from itertools import chain
+from solutions import BaseSolution
+
+
+class Solution(BaseSolution):
+    input_file = "10.txt"
+
+    def __str__(self):
+        return "Day 10: Elves Look, Elves Say"
+
+    def parse_input(self, data):
+        return data.strip()
+
+    def solve(self, puzzle_input, iterations=40):
+        return len(self._sequence(puzzle_input, iterations))
+
+    def solve_again(self, puzzle_input, iterations=50):
+        return len(self._sequence(puzzle_input, iterations))
+
+    def _sequence(self, sequence, iterations=40):
+        for _ in range(iterations):
+            chunks = []
+            v = sequence[0]
+            counter = 0
+            for c in sequence:
+                if c == v:
+                    counter += 1
+                else:
+                    chunks.append([str(counter), v])
+                    v = c
+                    counter = 1
+            chunks.append([str(counter), v])
+            sequence = "".join(chain(*chunks))
+        return sequence
+
+
+if __name__ == "__main__":
+    solution = Solution()
+    solution.show_results()
diff --git a/2015-python/tests/test_day_10.py b/2015-python/tests/test_day_10.py
new file mode 100644
index 0000000..db0cd85
--- /dev/null
+++ b/2015-python/tests/test_day_10.py
@@ -0,0 +1,31 @@
+import unittest
+
+from solutions.day_10 import Solution
+
+
+class Day10TestCase(unittest.TestCase):
+    def setUp(self):
+        self.solution = Solution()
+        self.puzzle_input = self.solution.parse_input(
+            """
+        <REPLACE ME>
+        """
+        )
+
+    def test_parse_puzzle_input(self):
+        data = """
+        12
+        """
+        assert self.solution.parse_input(data) == "12"
+
+    def test_solve_first_part(self):
+        assert self.solution._sequence("1", 1) == "11"
+        assert self.solution._sequence("11", 1) == "21"
+        assert self.solution._sequence("21", 1) == "1211"
+        assert self.solution._sequence("1211", 1) == "111221"
+        assert self.solution._sequence("111221", 1) == "312211"
+        assert self.solution._sequence("1", 5) == "312211"
+
+
+if __name__ == "__main__":
+    unittest.main()