solved(python): baekjoon 12850

Author: himitery

baekjoon/python/12850/__init__.py

@@ -0,0 +1,51 @@
+import sys
+
+read = lambda: sys.stdin.readline().rstrip()
+
+
+class Problem:
+    def __init__(self):
+        self.minutes = int(read())
+        self.matrix = [
+            [0, 1, 1, 0, 0, 0, 0, 0],
+            [1, 0, 1, 1, 0, 0, 0, 0],
+            [1, 1, 0, 1, 1, 0, 0, 0],
+            [0, 1, 1, 0, 1, 1, 0, 0],
+            [0, 0, 1, 1, 0, 1, 1, 0],
+            [0, 0, 0, 1, 1, 0, 0, 1],
+            [0, 0, 0, 0, 1, 0, 0, 1],
+            [0, 0, 0, 0, 0, 1, 1, 0],
+        ]
+
+        self.size = 8
+        self.mod = 1_000_000_007
+
+    def solve(self) -> None:
+        time, matrix, result = (
+            self.minutes,
+            self.matrix,
+            [[int(row == col) for col in range(self.size)] for row in range(self.size)],
+        )
+
+        while time > 0:
+            if time % 2 == 1:
+                result = self.matrix_multiply(result, matrix)
+            matrix = self.matrix_multiply(matrix, matrix)
+            time //= 2
+
+        print(result[0][0] % self.mod)
+
+    def matrix_multiply(self, matrix_a: list[list[int]], matrix_b: list[list[int]]) -> list[list[int]]:
+        result = [[0 for _ in range(self.size)] for _ in range(self.size)]
+
+        for x in range(self.size):
+            for y in range(self.size):
+                for z in range(self.size):
+                    result[x][y] += matrix_a[x][z] * matrix_b[z][y]
+                    result[x][y] %= self.mod
+
+        return result
+
+
+if __name__ == "__main__":
+    Problem().solve()

baekjoon/python/12850/main.py

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+[
+  {
+    "input": [
+      "100000000"
+    ],
+    "expected": [
+      "261245548"
+    ]
+  }
+]

baekjoon/python/12850/sample.json

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+import json
+import os.path
+import unittest
+from io import StringIO
+from unittest.mock import patch
+
+from parameterized import parameterized
+
+from main import Problem
+
+
+def load_sample(filename: str):
+    path = os.path.join(os.path.dirname(os.path.abspath(__file__)), filename)
+
+    with open(path, "r") as file:
+        return [(case["input"], case["expected"]) for case in json.load(file)]
+
+
+class TestCase(unittest.TestCase):
+    @parameterized.expand(load_sample("sample.json"))
+    def test_case(self, case: str, expected: list[str]):
+        # When
+        with (
+            patch("sys.stdin.readline", side_effect=case),
+            patch("sys.stdout", new_callable=StringIO) as output,
+        ):
+            Problem().solve()
+
+            result = output.getvalue().rstrip()
+
+        # Then
+        self.assertEqual("\n".join(expected), result)
+
+
+if __name__ == "__main__":
+    unittest.main()