solved(python): programmers

- 2025 프로그래머스 코드챌린지 1차 예선 / 홀짝트리

Author: himitery

programmers/2025_프로그래머스_코드챌린지_1차_예선/python/홀짝트리/__init__.py

@@ -0,0 +1,46 @@
+from collections import deque
+from typing import List, Dict, Set
+
+
+def solution(nodes: List[int], edges: List[List[int]]) -> List[int]:
+    graph = {node: set() for node in nodes}
+    for x, y in edges:
+        graph[x].add(y)
+        graph[y].add(x)
+
+    count, trees = [0, 0], find_trees(graph)
+    for tree in trees:
+        root_count, candidate = [0, 0], [None, None]
+
+        for node in tree:
+            tree_type = 1 - int(node % 2 == len(graph[node]) % 2)
+            root_count[tree_type] += 1
+            candidate[tree_type] = node
+
+        if root_count[0] == 1:
+            count[0] += 1
+        if root_count[1] == 1:
+            count[1] += 1
+
+    return count
+
+
+def find_trees(graph: Dict[int, Set[int]]) -> List[Set[int]]:
+    trees, visited = [], set()
+    for node in graph:
+        if node in visited:
+            continue
+
+        tree, queue = {node}, deque([node])
+        while queue:
+            node = queue.popleft()
+            visited.add(node)
+
+            for child in graph[node]:
+                if child not in visited:
+                    tree.add(child)
+                    queue.append(child)
+
+        trees.append(tree)
+
+    return trees

programmers/2025_프로그래머스_코드챌린지_1차_예선/python/홀짝트리/main.py

@@ -0,0 +1,92 @@
+[
+  {
+    "params": [
+      [
+        11,
+        9,
+        3,
+        2,
+        4,
+        6
+      ],
+      [
+        [
+          9,
+          11
+        ],
+        [
+          2,
+          3
+        ],
+        [
+          6,
+          3
+        ],
+        [
+          3,
+          4
+        ]
+      ]
+    ],
+    "expected": [
+      1,
+      0
+    ]
+  },
+  {
+    "params": [
+      [
+        9,
+        15,
+        14,
+        7,
+        6,
+        1,
+        2,
+        4,
+        5,
+        11,
+        8,
+        10
+      ],
+      [
+        [
+          5,
+          14
+        ],
+        [
+          1,
+          4
+        ],
+        [
+          9,
+          11
+        ],
+        [
+          2,
+          15
+        ],
+        [
+          2,
+          5
+        ],
+        [
+          9,
+          7
+        ],
+        [
+          8,
+          1
+        ],
+        [
+          6,
+          4
+        ]
+      ]
+    ],
+    "expected": [
+      2,
+      1
+    ]
+  }
+]

programmers/2025_프로그래머스_코드챌린지_1차_예선/python/홀짝트리/sample.json

@@ -0,0 +1,28 @@
+import json
+import os
+import unittest
+
+from parameterized import parameterized
+
+from .main import solution
+
+
+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["params"], case["expected"]) for case in json.load(file)]
+
+
+class TestCase(unittest.TestCase):
+    @parameterized.expand(load_sample("sample.json"))
+    def test_case(self, params: list, expected: any):
+        # When
+        result = solution(*params)
+
+        # Then
+        self.assertEqual(expected, result)
+
+
+if __name__ == "__main__":
+    unittest.main()