[mypy] Type annotations for graphs directory

graphs/breadth_first_search.py

@@ -53,7 +53,7 @@ def bfs(self, start_vertex: int) -> set[int]:
         visited = set()
 
         # create a first in first out queue to store all the vertices for BFS
-        queue = Queue()
+        queue: Queue = Queue()
 
         # mark the source node as visited and enqueue it
         visited.add(start_vertex)

graphs/breadth_first_search_2.py

@@ -32,7 +32,7 @@ def breadth_first_search(graph: dict, start: str) -> set[str]:
     'ABCDEF'
     """
     explored = {start}
-    queue = Queue()
+    queue: Queue = Queue()
     queue.put(start)
     while not queue.empty():
         v = queue.get()
@@ -44,4 +44,7 @@ def breadth_first_search(graph: dict, start: str) -> set[str]:
 
 
 if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()
     print(breadth_first_search(G, "A"))

graphs/check_cycle.py

@@ -6,16 +6,15 @@
 def check_cycle(graph: dict) -> bool:
     """
     Returns True if graph is cyclic else False
-
     >>> check_cycle(graph={0:[], 1:[0, 3], 2:[0, 4], 3:[5], 4:[5], 5:[]})
     False
     >>> check_cycle(graph={0:[1, 2], 1:[2], 2:[0, 3], 3:[3]})
     True
     """
     # Keep track of visited nodes
-    visited = set()
+    visited: set[int] = set()
     # To detect a back edge, keep track of vertices currently in the recursion stack
-    rec_stk = set()
+    rec_stk: set[int] = set()
     for node in graph:
         if node not in visited:
             if depth_first_search(graph, node, visited, rec_stk):
@@ -27,7 +26,6 @@ def depth_first_search(graph: dict, vertex: int, visited: set, rec_stk: set) ->
     """
     Recur for all neighbours.
     If any neighbour is visited and in rec_stk then graph is cyclic.
-
     >>> graph = {0:[], 1:[0, 3], 2:[0, 4], 3:[5], 4:[5], 5:[]}
     >>> vertex, visited, rec_stk = 0, set(), set()
     >>> depth_first_search(graph, vertex, visited, rec_stk)

mypy.ini

@@ -2,4 +2,4 @@
 ignore_missing_imports = True
 install_types = True
 non_interactive = True
-exclude = (graphs/breadth_first_search.py|graphs/breadth_first_search_2.py|graphs/check_cycle.py|graphs/greedy_min_vertex_cover.py|matrix_operation.py|other/least_recently_used.py|other/lfu_cache.py|other/lru_cache.py|searches/simulated_annealing.py|searches/ternary_search.py)
+exclude = (graphs/check_cycle.py|graphs/greedy_min_vertex_cover.py|matrix_operation.py|other/least_recently_used.py|other/lfu_cache.py|other/lru_cache.py|searches/simulated_annealing.py|searches/ternary_search.py)