Fix backtrack time complexity (TheAlgorithms#965)

Erfaniaa · web-flow · commit 69bed590368a · 2019-07-06T20:01:52.000+04:30
* Update backtracking/all_permutations.py
diff --git a/backtracking/all_permutations.py b/backtracking/all_permutations.py
@@ -2,7 +2,7 @@
 	In this problem, we want to determine all possible permutations
 	of the given sequence. We use backtracking to solve this problem.
 
-	Time complexity: O(n!),
+	Time complexity: O(n! * n),
 	where n denotes the length of the given sequence.
 '''
 
