From 000001505b2873db7e13420a30bd05d7ea73ae17 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Matej=20Jane=C5=BEi=C4=8D?= <janezic.mj@gmail.com>
Date: Sun, 7 Dec 2025 06:45:25 +0100
Subject: [PATCH] feat: add solution 2025/07

---
 data/example/2025/07.txt         | 16 +++++++++
 src/solution/year_2025/day_07.py | 56 ++++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)
 create mode 100644 data/example/2025/07.txt
 create mode 100644 src/solution/year_2025/day_07.py

diff --git a/data/example/2025/07.txt b/data/example/2025/07.txt
new file mode 100644
index 000000000..57a2466
--- /dev/null
+++ b/data/example/2025/07.txt
@@ -0,0 +1,16 @@
+.......S.......
+...............
+.......^.......
+...............
+......^.^......
+...............
+.....^.^.^.....
+...............
+....^.^...^....
+...............
+...^.^...^.^...
+...............
+..^...^.....^..
+...............
+.^.^.^.^.^...^.
+...............
diff --git a/src/solution/year_2025/day_07.py b/src/solution/year_2025/day_07.py
new file mode 100644
index 000000000..e744851
--- /dev/null
+++ b/src/solution/year_2025/day_07.py
@@ -0,0 +1,56 @@
+from functools import lru_cache
+from typing import Any
+
+
+def part_1(input_data: str) -> Any:
+    lines = input_data.splitlines()
+    first, rest = lines[0], lines[1:]
+
+    s = {i for i, x in enumerate(first) if x == "S"}
+    ns: set[int] = set()
+
+    c = 0
+    for line in rest:
+        ns.clear()
+
+        while s:
+            n = s.pop()
+            if line[n] == "^":
+                ns.add(n - 1)
+                ns.add(n + 1)
+                c += 1
+            else:
+                ns.add(n)
+
+        s.update(ns)
+
+    return c
+
+
+def trace_path(n: int, i: int, lines: list[str]) -> int:
+    @lru_cache(None)
+    def aux(n: int, i: int) -> int:
+        for idx, line in filter(lambda x: x[0] >= i, enumerate(lines)):
+            if line[n] == "^":
+                left = aux(n - 1, idx + 1)
+                right = aux(n + 1, idx + 1)
+                return 1 + left + right
+
+        return 0
+
+    return aux(n, i)
+
+
+def part_2(input_data: str) -> Any:
+    lines = input_data.splitlines()
+    first, rest = lines[0], lines[1:]
+    n = next(filter(lambda x: x[1] == "S", enumerate(first)))[0]
+    return 1 + trace_path(n, 0, rest)
+
+
+def test_part_1(example_data):
+    assert part_1(example_data) == 21
+
+
+def test_part_2(example_data):
+    assert part_2(example_data) == 40