From ad048c7c7564f5b2234aa7d05a0597a00b98576b Mon Sep 17 00:00:00 2001
From: dholmes4 <dholmes4@huskers.unl.edu>
Date: Thu, 27 Mar 2025 16:34:48 -0500
Subject: [PATCH] finalized lab. i'm not doing the bonus may god have mercy on
me for not doing so
---
lab - linked list lab/linked_list_example.py | 79 +++++++++++++++++---
1 file changed, 70 insertions(+), 9 deletions(-)
diff --git a/lab - linked list lab/linked_list_example.py b/lab - linked list lab/linked_list_example.py
index 356f92f..565e9e4 100644
--- a/lab - linked list lab/linked_list_example.py
+++ b/lab - linked list lab/linked_list_example.py
@@ -75,9 +75,6 @@ class LinkedStack(object):
def is_empty(self):
return self.head is None
-def main():
- test_linked_queue_duncan_version()
-
def test_linked_stack_duncan_version():
testing_stack = LinkedStack()
print("testing_stack : "+str( testing_stack ) )
@@ -209,7 +206,7 @@ class LinkedDeque(object):
implementation is very similar to code you wrote earlier.)
"""
def add_back(self, item):
- new_node = Node(item)
+ new_node = doubly_linked_node(item)
if self.head is None:
self.head = new_node
self.tail = new_node
@@ -226,7 +223,7 @@ class LinkedDeque(object):
for cleanly dealing with this kind of DRY problem.)
"""
def add_front(self, item):
- new_node = Node(item)
+ new_node = doubly_linked_node(item)
if self.head is None:
self.head = new_node
self.tail = new_node
@@ -240,17 +237,44 @@ class LinkedDeque(object):
item from the front of the deque.
"""
def remove_front(self):
+ """
+ this also works but it's best to have symmetry with the twin removes
+
returnValue = self.head.item
self.head = self.head.next_node
return returnValue
+ """
+ if self.head is None:
+ raise IndexError("Deque is empty!")
+
+ returnValue = self.head.item
+
+ if self.head == self.tail:
+ self.head = None
+ self.tail = None
+ else:
+ self.head = self.head.next_node
+ self.head.previous_node = None
+
+ return returnValue
"""
Implement a remove_back method that removes and returns an
item from the back of the deque.
"""
def remove_back(self):
+ if self.tail is None:
+ raise IndexError("Deque is empty!")
+
returnValue = self.tail.item
- self.tail = self.tail.previous_node
+
+ if self.tail == self.head:
+ self.head = None
+ self.tail = None
+ else:
+ self.tail = self.tail.previous_node
+ self.tail.next_node = None
+
return returnValue
"""
@@ -260,19 +284,56 @@ class LinkedDeque(object):
return self.head is None
def print_linked_list(self):
+
+ string_spit_out = ""
+
current_node = self.head
while current_node is not None:
- print(current_node.item)
+ string_spit_out += str(current_node.item) + " "
current_node = current_node.next_node
+ print(f"Our deque String as a whole is \n{string_spit_out}")
+
def test_linked_deque_duncan_version():
+
+ """
+ load it up frontwards
+ """
testing_linked_deque = LinkedDeque()
- testing_linked_deque.add_front(1)
- testing_linked_deque.add_front(2)
testing_linked_deque.add_front(3)
+ testing_linked_deque.add_front(2)
+ testing_linked_deque.add_front(1)
+
+ #see that it's structured correclty
+ testing_linked_deque.print_linked_list()
+
+ print("\n")
+ #unload it
+ while not testing_linked_deque.is_empty():
+ testing_linked_deque.remove_front()
+
+ testing_linked_deque.add_back(1)
+ testing_linked_deque.add_back(2)
+ testing_linked_deque.add_back(3)
testing_linked_deque.print_linked_list()
+ print("\ni'm gonna take 1 from the front")
+ testing_linked_deque.remove_front()
+ testing_linked_deque.print_linked_list()
+
+ print("\nreplacing the 1 i just took away ")
+ testing_linked_deque.add_front(1)
+ testing_linked_deque.print_linked_list()
+
+ print("\ni'm gonna take 3 from the back")
+ testing_linked_deque.remove_back()
+ testing_linked_deque.print_linked_list()
+
+
+def main():
+ test_linked_deque_duncan_version()
+
if __name__ == "__main__":
main()
\ No newline at end of file
--
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