solved(python): baekjoon 1504

Author: himitery

baekjoon/python/1504/__init__.py

@@ -0,0 +1,68 @@
+import heapq
+import sys
+
+from collections import defaultdict
+
+read = lambda: sys.stdin.readline().rstrip()
+
+
+class Problem:
+    def __init__(self):
+        self.n, self.e = map(int, read().split())
+
+        self.graph = defaultdict(list)
+        for src, dest, distance in [map(int, read().split()) for _ in range(self.e)]:
+            self.graph[src - 1].append((dest - 1, distance))
+            self.graph[dest - 1].append((src - 1, distance))
+
+        self.stopover = list(map(lambda x: int(x) - 1, read().split()))
+
+    def solve(self) -> None:
+        print(
+            min(
+                self.calculate_total_distance(
+                    [
+                        (0, self.stopover[0]),
+                        (self.stopover[0], self.stopover[1]),
+                        (self.stopover[1], self.n - 1),
+                    ]
+                ),
+                self.calculate_total_distance(
+                    [
+                        (0, self.stopover[1]),
+                        (self.stopover[1], self.stopover[0]),
+                        (self.stopover[0], self.n - 1),
+                    ]
+                ),
+            )
+        )
+
+    def dijkstra(self, start: int, end: int) -> int:
+        if start == end:
+            return 0
+
+        heap, distances = [(0, start)], [-1] * (self.n + 1)
+
+        while heap:
+            current_distance, current_vertex = heapq.heappop(heap)
+            if current_vertex == end:
+                return distances[end]
+
+            if distances[current_vertex] is not -1 and current_distance > distances[current_vertex]:
+                continue
+
+            for next_vertex, distance in self.graph[current_vertex]:
+                if distances[next_vertex] is -1 or current_distance + distance < distances[next_vertex]:
+                    distances[next_vertex] = current_distance + distance
+                    heapq.heappush(heap, (current_distance + distance, next_vertex))
+
+        return -1
+
+    def calculate_total_distance(self, paths: list[tuple[int, int]]) -> int:
+        distances = [self.dijkstra(path[0], path[1]) for path in paths]
+
+        return -1 if any(distance == -1 for distance in distances) else sum(distances)
+
+
+if __name__ == "__main__":
+    Problem().solve()

baekjoon/python/1504/main.py

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+[
+  {
+    "input": [
+      "4 6",
+      "1 2 3",
+      "2 3 3",
+      "3 4 1",
+      "1 3 5",
+      "2 4 5",
+      "1 4 4",
+      "2 3"
+    ],
+    "expected": [
+      "7"
+    ]
+  }
+]

baekjoon/python/1504/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()