derek.holloway
59 lines
3.0 KiB
Python
59 lines
3.0 KiB
Python
# This is the node definition. Allowing each 'chain link' to hold data and point to the next
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class DerekLinkedListNode:
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def __init__(self, key, item) -> None:
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self.key = key
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self.data = item
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self.next: DerekLinkedListNode | None = None
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# This is the real meat of the linked list
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class DerekLinkedList:
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# On init point to the first node and hold the total length
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def __init__(self) -> None:
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self.head: DerekLinkedListNode | None = None
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self.len: int = 0
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def __iter__(self):
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current = self.head # Set the head of the linked list
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while current: # if the value exists
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yield current.data # return the data
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current = current.next # set the next link
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# Appends an item to the end of the list
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def append(self, key, item) -> None:
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self.len += 1 # update the overall length
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newNode = DerekLinkedListNode(key, item) # create the node to insert
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if not self.head: # if the head doesnt exist
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self.head = newNode # set the head as the node and return
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return
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cur = self.head # if the head exists set cur to the next node
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while cur.next: # loop through the rest of the chain looking for the end
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cur = cur.next
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cur.next = newNode # add the new node to the end
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# Removes an item at the index
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def remove(self, key) -> None:
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lastNode = self.head # previous node
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curNode = self.head # current node
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while key != curNode.key: # get to the node we are curious about
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lastNode = curNode
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if curNode.next == None:
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return None
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curNode = curNode.next
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if curNode == self.head:
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self.head = curNode.next
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else:
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lastNode.next = curNode.next # pull the current node out of the linked list
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self.len -= 1 # remove the length by 1
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# returns the data at the index
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def get(self, key):
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if self.head: # if the head exists
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cur: DerekLinkedListNode | None = self.head # set the current searching for at the head
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while key != cur.key: # go through the chain until we hit the index were looking for
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if cur.next == None:
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return
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cur = cur.next
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if isinstance(cur, DerekLinkedListNode): # since we made it here the data were on is a LinkedListNode
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return cur.data # return the value out of the node
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else:
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return None |