solved(python): baekjoon 1533

Author: himitery

baekjoon/python/1533/__init__.py

@@ -0,0 +1,57 @@
+import itertools
+import sys
+
+read = lambda: sys.stdin.readline().rstrip()
+
+
+class Problem:
+    def __init__(self):
+        self.n, self.s, self.e, self.t = map(int, read().split())
+        self.matrix = [list(map(int, list(read()))) for _ in range(self.n)]
+
+        self.mod = 1_000_003
+        self.size = self.n * 5
+
+    def solve(self) -> None:
+        time, matrix, result = (
+            self.t,
+            self.build_expanded_matrix(),
+            [[int(i == j) for j in range(self.size)] for i 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[(self.e - 1) * 5][(self.s - 1) * 5] % self.mod)
+
+    def build_expanded_matrix(self) -> list[list[int]]:
+        matrix = [[0] * self.size for _ in range(self.size)]
+
+        for idx, time in itertools.product(range(self.n), range(4)):
+            matrix[idx * 5 + time + 1][idx * 5 + time] = 1
+
+        for x, y in itertools.product(range(self.n), range(self.n)):
+            if (delay := self.matrix[x][y]) and delay > 0:
+                matrix[y * 5][x * 5 + (delay - 1)] = 1
+
+        return matrix
+
+    def matrix_multiply(self, matrix_x: list[list[int]], matrix_y: list[list[int]]) -> list[list[int]]:
+        result = [[0 for _ in range(self.size)] for _ in range(self.size)]
+
+        for x, y in itertools.product(range(self.size), range(self.size)):
+            if matrix_x[x][y] == 0:
+                continue
+
+            for z in range(self.size):
+                result[x][z] += matrix_x[x][y] * matrix_y[y][z]
+                result[x][z] %= self.mod
+
+        return result
+
+
+if __name__ == "__main__":
+    Problem().solve()

baekjoon/python/1533/main.py

@@ -0,0 +1,13 @@
+[
+  {
+    "input": [
+      "3 1 3 5",
+      "012",
+      "201",
+      "120"
+    ],
+    "expected": [
+      "8"
+    ]
+  }
+]

baekjoon/python/1533/sample.json

@@ -0,0 +1,36 @@
+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()