solved(python): baekjoon 2618

Author: himitery

baekjoon/python/2618/__init__.py

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+import itertools
+import math
+import sys
+
+read = lambda: sys.stdin.readline().rstrip()
+
+
+class Problem:
+    def __init__(self):
+        self.n, self.w = int(read()), int(read())
+        self.coords = [(0, 0)]
+        for _ in range(self.w):
+            y, x = map(int, read().split())
+            self.coords.append((x - 1, y - 1))
+
+    def solve(self) -> None:
+        dp, path, parent = (
+            [[math.inf for _ in range(self.w + 1)] for _ in range(self.w + 1)],
+            [[0 for _ in range(self.w + 1)] for _ in range(self.w + 1)],
+            [[(0, 0)] * (self.w + 1) for _ in range(self.w + 1)],
+        )
+        dp[0][0] = 0
+
+        for x, y in itertools.product(range(self.w + 1), repeat=2):
+            event = max(x, y) + 1
+            if event > self.w:
+                continue
+
+            cost_x = dp[x][y] + self.calc_distance((0, 0) if x == 0 else self.coords[x], event)
+            if cost_x < dp[event][y]:
+                dp[event][y], path[event][y], parent[event][y] = cost_x, 1, (x, y)
+
+            cost_y = dp[x][y] + self.calc_distance((self.n - 1, self.n - 1) if y == 0 else self.coords[y], event)
+            if cost_y < dp[x][event]:
+                dp[x][event], path[x][event], parent[x][event] = cost_y, 2, (x, y)
+
+        minimum, x, y = math.inf, 0, 0
+        for idx in range(self.w + 1):
+            if dp[idx][self.w] < minimum:
+                minimum, x, y = dp[idx][self.w], idx, self.w
+            if dp[self.w][idx] < minimum:
+                minimum, x, y = dp[self.w][idx], self.w, idx
+
+        sequence = []
+        for _ in range(self.w):
+            sequence.append(path[x][y])
+            x, y = parent[x][y]
+
+        print(minimum)
+        print(*reversed(sequence), sep="\n")
+
+    def calc_distance(self, src: tuple[int, int], dist_idx: int) -> int:
+        return abs(src[0] - self.coords[dist_idx][0]) + abs(src[1] - self.coords[dist_idx][1])
+
+
+if __name__ == "__main__":
+    Problem().solve()

baekjoon/python/2618/main.py

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+[
+  {
+    "input": [
+      "6",
+      "3",
+      "3 5",
+      "5 5",
+      "2 3"
+    ],
+    "expected": [
+      "9",
+      "2",
+      "2",
+      "1"
+    ]
+  }
+]

baekjoon/python/2618/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()