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

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

Author: pre-commit-ci[bot]

backtracking/hamiltonian_cycle.py

@@ -175,6 +175,7 @@ def hamilton_cycle(graph: list[list[int]], start_index: int = 0) -> list[int]:
     # evaluate and if we find answer return path either return empty array
     return path if util_hamilton_cycle(graph, path, 1) else []
 
+
 if __name__ == "__main__":
     import doctest
 
@@ -186,4 +187,4 @@ def hamilton_cycle(graph: list[list[int]], start_index: int = 0) -> list[int]:
         [1, 1, 0, 0, 1],
         [0, 1, 1, 1, 0],
     ]
-    print(hamilton_cycle(graph))
+    print(hamilton_cycle(graph))