#9943 : Adding coverage test for basic_graphs.py (#12354)

* #9943 : Adding coverage test for basic_graphs.py

* #9943 : Adding coverage test for basic_graphs.py

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Solve problem of line too long

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

graphs/basic_graphs.py

@@ -77,6 +77,14 @@ def initialize_weighted_undirected_graph(
 
 
 def dfs(g, s):
+    """
+    >>> dfs({1: [2, 3], 2: [4, 5], 3: [], 4: [], 5: []}, 1)
+    1
+    2
+    4
+    5
+    3
+    """
     vis, _s = {s}, [s]
     print(s)
     while _s:
@@ -104,6 +112,17 @@ def dfs(g, s):
 
 
 def bfs(g, s):
+    """
+    >>> bfs({1: [2, 3], 2: [4, 5], 3: [6, 7], 4: [], 5: [8], 6: [], 7: [], 8: []}, 1)
+    1
+    2
+    3
+    4
+    5
+    6
+    7
+    8
+    """
     vis, q = {s}, deque([s])
     print(s)
     while q:
@@ -128,6 +147,19 @@ def bfs(g, s):
 
 
 def dijk(g, s):
+    """
+    dijk({1: [(2, 7), (3, 9), (6, 14)],
+        2: [(1, 7), (3, 10), (4, 15)],
+        3: [(1, 9), (2, 10), (4, 11), (6, 2)],
+        4: [(2, 15), (3, 11), (5, 6)],
+        5: [(4, 6), (6, 9)],
+        6: [(1, 14), (3, 2), (5, 9)]}, 1)
+    7
+    9
+    11
+    20
+    20
+    """
     dist, known, path = {s: 0}, set(), {s: 0}
     while True:
         if len(known) == len(g) - 1: