From 050a0af7abbf9e683092b7f03426225ed1f3a4be Mon Sep 17 00:00:00 2001
From: Tarun Vishwakarma <tarunvishwakarma81@gmail.com>
Date: Mon, 14 Oct 2024 12:12:44 +0530
Subject: [PATCH] Added test for edmonds_blossom_algorithm.py in graph/tests/

Resolved the blossom data naming issue.
---
 graphs/edmonds_blossom_algorithm.py           | 23 ++++--
 .../tests/test_edmonds_blossom_algorithm.py   | 72 +++++++++++++++++++
 2 files changed, 88 insertions(+), 7 deletions(-)
 create mode 100644 graphs/tests/test_edmonds_blossom_algorithm.py

diff --git a/graphs/edmonds_blossom_algorithm.py b/graphs/edmonds_blossom_algorithm.py
index 8488f375a..6ec681d39 100644
--- a/graphs/edmonds_blossom_algorithm.py
+++ b/graphs/edmonds_blossom_algorithm.py
@@ -173,7 +173,7 @@ class EdmondsBlossomAlgorithm:
         >>> EdmondsBlossomAlgorithm.contract_blossom(blossom_data)
         """
         # Mark all vertices in the blossom
-        current_vertex_u = blossom_data.u
+        current_vertex_u = blossom_data.vertex_u
         while blossom_data.aux_data.base[current_vertex_u] != blossom_data.lca:
             base_u = blossom_data.aux_data.base[current_vertex_u]
             match_base_u = blossom_data.aux_data.base[blossom_data.aux_data.match
@@ -185,7 +185,7 @@ class EdmondsBlossomAlgorithm:
                 blossom_data.aux_data.match[current_vertex_u]
             ]
 
-        current_vertex_v = blossom_data.v
+        current_vertex_v = blossom_data.vertex_v
         while blossom_data.aux_data.base[current_vertex_v] != blossom_data.lca:
             base_v = blossom_data.aux_data.base[current_vertex_v]
             match_base_v = blossom_data.aux_data.base[blossom_data.aux_data.match
@@ -228,9 +228,18 @@ class BlossomData:
     BlossomData class with reduced parameters.
     """
 
-    def __init__(self, aux_data: BlossomAuxData, u: int, v: int, lca: int) -> None:
-        self.aux_data = aux_data
-        self.u = u
-        self.v = v
-        self.lca = lca
+    def __init__(self, aux_data: BlossomAuxData, vertex_u: int,
+                 vertex_v: int, lca: int) -> None:
+        """
+        Initialize BlossomData with auxiliary data, two vertices,
+        and the lowest common ancestor.
 
+        :param aux_data: Auxiliary data used in the algorithm
+        :param vertex_u: First vertex involved in the blossom
+        :param vertex_v: Second vertex involved in the blossom
+        :param lca: Lowest common ancestor (base) of the two vertices
+        """
+        self.aux_data = aux_data
+        self.vertex_u = vertex_u
+        self.vertex_v = vertex_v
+        self.lca = lca
diff --git a/graphs/tests/test_edmonds_blossom_algorithm.py b/graphs/tests/test_edmonds_blossom_algorithm.py
new file mode 100644
index 000000000..661533d21
--- /dev/null
+++ b/graphs/tests/test_edmonds_blossom_algorithm.py
@@ -0,0 +1,72 @@
+import unittest
+from collections import deque
+
+from graphs.edmonds_blossom_algorithm import (
+    UNMATCHED,
+    BlossomAuxData,
+    BlossomData,
+    EdmondsBlossomAlgorithm,
+)
+
+
+class TestEdmondsBlossomAlgorithm(unittest.TestCase):
+
+    def test_maximum_matching(self):
+        # Test case: Basic matching in a simple graph
+        edges = [(0, 1), (1, 2), (2, 3)]
+        vertex_count = 4
+        result = EdmondsBlossomAlgorithm.maximum_matching(edges, vertex_count)
+        expected_result = [(0, 1), (2, 3)]
+        assert result == expected_result
+
+        # Test case: Graph with no matching
+        edges = []
+        vertex_count = 4
+        result = EdmondsBlossomAlgorithm.maximum_matching(edges, vertex_count)
+        expected_result = []
+        assert result == expected_result
+
+    def test_update_matching(self):
+        # Test case: Update matching on a simple augmenting path
+        match = [UNMATCHED, UNMATCHED, UNMATCHED]
+        parent = [1, 0, UNMATCHED]
+        current_vertex = 2
+        EdmondsBlossomAlgorithm.update_matching(match, parent, current_vertex)
+        expected_result = [1, 0, UNMATCHED]
+        assert match == expected_result
+
+    def test_find_base(self):
+        # Test case: Find base of blossom
+        base = [0, 1, 2, 3]
+        parent = [1, 0, UNMATCHED, UNMATCHED]
+        vertex_u = 2
+        vertex_v = 3
+        result = EdmondsBlossomAlgorithm.find_base(base, parent, vertex_u, vertex_v)
+        expected_result = 2
+        assert result == expected_result
+
+    def test_contract_blossom(self):
+        # Test case: Contracting a simple blossom
+        queue = deque()
+        parent = [UNMATCHED, UNMATCHED, UNMATCHED]
+        base = [0, 1, 2]
+        in_blossom = [False] * 3
+        match = [UNMATCHED, UNMATCHED, UNMATCHED]
+        in_queue = [False] * 3
+        aux_data = BlossomAuxData(queue, parent, base, in_blossom, match, in_queue)
+        blossom_data = BlossomData(aux_data, 0, 1, 2)
+
+        # Contract the blossom
+        EdmondsBlossomAlgorithm.contract_blossom(blossom_data)
+
+        # Ensure base is updated correctly
+        assert aux_data.base == [2, 2, 2]
+        # Check that the queue has the contracted vertices
+        assert 0 in aux_data.queue
+        assert 1 in aux_data.queue
+        assert aux_data.in_queue[0]
+        assert aux_data.in_queue[1]
+
+
+if __name__ == '__main__':
+    unittest.main()