Merge branch 'feature/bfs-test' into develop

Author: codejsha

README.md

@@ -210,7 +210,7 @@ algorithm BellmanFord(G, source):
     return true
 ```
 
-- Breadth-first search (BFS): [c++](cpp-algorithm/src/graph), [java](java-algorithm/src/main/java/com/example/algorithm/graph) | A search algorithm that traverses a graph layer by layer. Check the shortest path and compute the distance from the source vertex to all other vertices.
+- Breadth-first search (BFS), CCSP#4.3.1: [c++](cpp-algorithm/src/graph), [java](java-algorithm/src/main/java/com/example/algorithm/graph), [python(test)](python-algorithm/algorithm/graph/test) | A search algorithm that traverses a graph layer by layer. Check the shortest path and compute the distance from the source vertex to all other vertices.
 
 ```txt
 algorithm BFS(G, source):

python-algorithm/algorithm/graph/__init__.py

@@ -0,0 +1,78 @@
+import pytest, networkx
+
+
+def create_city_graph() -> networkx.Graph:
+    graph = networkx.Graph()
+    graph.add_edge("Seattle", "Chicago")
+    graph.add_edge("Seattle", "San Francisco")
+    graph.add_edge("San Francisco", "Riverside")
+    graph.add_edge("San Francisco", "Los Angeles")
+    graph.add_edge("Los Angeles", "Riverside")
+    graph.add_edge("Los Angeles", "Phoenix")
+    graph.add_edge("Riverside", "Phoenix")
+    graph.add_edge("Riverside", "Chicago")
+    graph.add_edge("Phoenix", "Dallas")
+    graph.add_edge("Phoenix", "Houston")
+    graph.add_edge("Dallas", "Chicago")
+    graph.add_edge("Dallas", "Atlanta")
+    graph.add_edge("Dallas", "Houston")
+    graph.add_edge("Houston", "Atlanta")
+    graph.add_edge("Houston", "Miami")
+    graph.add_edge("Atlanta", "Chicago")
+    graph.add_edge("Atlanta", "Washington")
+    graph.add_edge("Atlanta", "Miami")
+    graph.add_edge("Miami", "Washington")
+    graph.add_edge("Chicago", "Detroit")
+    graph.add_edge("Detroit", "Boston")
+    graph.add_edge("Detroit", "Washington")
+    graph.add_edge("Detroit", "New York")
+    graph.add_edge("Boston", "New York")
+    graph.add_edge("New York", "Philadelphia")
+    graph.add_edge("Philadelphia", "Washington")
+    return graph
+
+
+city_graph = create_city_graph()
+
+
+@pytest.mark.benchmark(group='graph_neighbors')
+@pytest.mark.parametrize(
+    argnames='graph, source, expected',
+    argvalues=[
+        (city_graph, "Seattle", ["Chicago", "San Francisco"]),
+        (city_graph, "San Francisco", ["Seattle", "Riverside", "Los Angeles"]),
+        (city_graph, "Los Angeles", ["San Francisco", "Riverside", "Phoenix"]),
+        (city_graph, "Riverside", ["San Francisco", "Los Angeles", "Phoenix", "Chicago"]),
+        (city_graph, "Phoenix", ["Los Angeles", "Riverside", "Dallas", "Houston"]),
+        (city_graph, "Chicago", ["Seattle", "Riverside", "Dallas", "Atlanta", "Detroit"]),
+        (city_graph, "Boston", ["Detroit", "New York"]),
+        (city_graph, "New York", ["Detroit", "Boston", "Philadelphia"]),
+        (city_graph, "Atlanta", ["Dallas", "Houston", "Chicago", "Washington", "Miami"]),
+        (city_graph, "Miami", ["Houston", "Atlanta", "Washington"]),
+        (city_graph, "Dallas", ["Phoenix", "Chicago", "Atlanta", "Houston"]),
+        (city_graph, "Houston", ["Phoenix", "Dallas", "Atlanta", "Miami"]),
+        (city_graph, "Detroit", ["Chicago", "Boston", "Washington", "New York"]),
+        (city_graph, "Philadelphia", ["New York", "Washington"]),
+        (city_graph, "Washington", ["Atlanta", "Miami", "Detroit", "Philadelphia"])
+    ])
+def test_graph_neighbors(benchmark, graph, source, expected):
+    result = benchmark(graph.neighbors, source)
+    assert sorted(expected) == sorted(result)
+
+
+@pytest.mark.benchmark(group='graph_breadth_first_search')
+@pytest.mark.parametrize(
+    argnames='graph, source, distance, expected',
+    argvalues=[
+        (city_graph, "Boston", 1, ["Detroit", "New York"]),
+        (city_graph, "Boston", 2, ["Chicago", "Washington", "Philadelphia"]),
+        (city_graph, "Boston", 3, ["Seattle", "Riverside", "Dallas", "Atlanta", "Miami"]),
+    ],
+    ids=["distance1", "distance2", "distance3"])
+def test_graph_breadth_first_search(benchmark, graph, source, distance, expected):
+    bfs_generator = benchmark(networkx.bfs_layers, graph, source)
+    path = []
+    for i, layer in enumerate(bfs_generator):
+        if i == distance:
+            path = list(layer)
+    assert path == expected