From 571e2d8cf2a45ff5e41509de36b9627c682fbb78 Mon Sep 17 00:00:00 2001 From: Amirsoroush Date: Sat, 1 Apr 2023 14:42:41 +0300 Subject: [PATCH] remove extra length check in doubly-linked-list's methods --- data_structures/linked_list/doubly_linked_list.py | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/data_structures/linked_list/doubly_linked_list.py b/data_structures/linked_list/doubly_linked_list.py index 41d07d63e005..69763d12da15 100644 --- a/data_structures/linked_list/doubly_linked_list.py +++ b/data_structures/linked_list/doubly_linked_list.py @@ -81,7 +81,9 @@ def insert_at_nth(self, index: int, data): .... IndexError: list index out of range """ - if not 0 <= index <= len(self): + length = len(self) + + if not 0 <= index <= length: raise IndexError("list index out of range") new_node = Node(data) if self.head is None: @@ -90,7 +92,7 @@ def insert_at_nth(self, index: int, data): self.head.previous = new_node new_node.next = self.head self.head = new_node - elif index == len(self): + elif index == length: self.tail.next = new_node new_node.previous = self.tail self.tail = new_node @@ -131,15 +133,17 @@ def delete_at_nth(self, index: int): .... IndexError: list index out of range """ - if not 0 <= index <= len(self) - 1: + length = len(self) + + if not 0 <= index <= length - 1: raise IndexError("list index out of range") delete_node = self.head # default first node - if len(self) == 1: + if length == 1: self.head = self.tail = None elif index == 0: self.head = self.head.next self.head.previous = None - elif index == len(self) - 1: + elif index == length - 1: delete_node = self.tail self.tail = self.tail.previous self.tail.next = None