solved(python): baekjoon 3830

Author: himitery

baekjoon/python/3830/__init__.py

@@ -0,0 +1,50 @@
+import sys
+
+read = lambda: sys.stdin.readline().rstrip()
+
+
+class Problem:
+    def __init__(self):
+        self.n, self.m = map(int, read().split())
+        self.queries = []
+        for line in [read().split() for _ in range(self.m)]:
+            self.queries.append((line[0] == "?", list(map(int, line[1:]))))
+
+        self.parent, self.weight = list(range(self.n + 1)), [0] * (self.n + 1)
+
+    def solve(self) -> None:
+        for is_query, args in self.queries:
+            if not is_query:
+                self.union(*args)
+                continue
+
+            x, y = args
+            print("UNKNOWN" if self.find(x) != self.find(y) else self.weight[y] - self.weight[x])
+
+    def find(self, num: int) -> int:
+        path = []
+        while self.parent[num] != num:
+            path.append(num)
+            num = self.parent[num]
+
+        for node in reversed(path):
+            self.weight[node] += self.weight[self.parent[node]]
+            self.parent[node] = num
+
+        return num
+
+    def union(self, x: int, y: int, weight: int) -> None:
+        root_x, root_y = self.find(x), self.find(y)
+        if root_x != root_y:
+            self.parent[root_y] = root_x
+            self.weight[root_y] = self.weight[x] - self.weight[y] + weight
+
+
+if __name__ == "__main__":
+    while True:
+        try:
+            Problem().solve()
+        except StopIteration:
+            break
+        except (EOFError, ValueError):
+            break

baekjoon/python/3830/main.py

@@ -0,0 +1,29 @@
+[
+  {
+    "input": [
+      "2 2",
+      "! 1 2 1",
+      "? 1 2",
+      "2 2",
+      "! 1 2 1",
+      "? 2 1",
+      "4 7",
+      "! 1 2 100",
+      "? 2 3",
+      "! 2 3 100",
+      "? 2 3",
+      "? 1 3",
+      "! 4 3 150",
+      "? 4 1",
+      "0 0"
+    ],
+    "expected": [
+      "1",
+      "-1",
+      "UNKNOWN",
+      "100",
+      "200",
+      "-50"
+    ]
+  }
+]

baekjoon/python/3830/sample.json

@@ -0,0 +1,40 @@
+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,
+        ):
+            while True:
+                try:
+                    Problem().solve()
+                except StopIteration:
+                    break
+
+            result = output.getvalue().rstrip()
+
+        # Then
+        self.assertEqual("\n".join(expected), result)
+
+
+if __name__ == "__main__":
+    unittest.main()