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jsgoller1jsgoller1
committedMay 8, 2023
wokring on btree
1 parent 4a56b3a commit dcd9b31

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4 files changed

+239
-51
lines changed

4 files changed

+239
-51
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‎notebooks/B-Tree.ipynb

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{
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"cells": [
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{
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"cell_type": "code",
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"execution_count": 35,
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"id": "destroyed-ground",
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"metadata": {},
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"outputs": [],
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"source": [
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"from abc import ABC, abstractmethod\n",
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"import bisect"
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]
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},
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{
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"cell_type": "code",
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"execution_count": 5,
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"id": "matched-tract",
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"metadata": {},
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"outputs": [],
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"source": [
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"class BPlusTreeNode(ABC):\n",
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" def __init__(self, kvstore = None, is_leaf = False):\n",
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" self._kvstore = kvstore if kvstore else []\n",
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" self._is_leaf = is_leaf\n",
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" \n",
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" \n",
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" def delete(self, key):\n",
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" idx = -1\n",
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" for i, tup in enumerate(self._kvstore):\n",
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" k, _ = tup\n",
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" if k == key:\n",
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" idx = i\n",
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" if idx != -1:\n",
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" del self._kvstore[idx]\n",
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" \n",
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" \n",
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" def find(self, key):\n",
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" # TODO: Use binary search here instead;\n",
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" # look into using bisect.bisect_left\n",
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" for k,v in self._kvstore:\n",
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" if k == key:\n",
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" return (k,v)\n",
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" return None\n",
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"\n",
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" \n",
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" def order(self):\n",
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" return len(self._kvstore) \n",
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"\n",
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" def insert(self, key_or_tuple, value=None):\n",
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" \"\"\"\n",
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" TODO: Maybe we should implement this in the child classes\n",
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" since \n",
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" \"\"\"\n",
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" if isinstance(key_or_tuple, tuple) and value is None:\n",
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" key, value = key_or_tuple\n",
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" elif not isinstance(key_or_tuple, tuple) and value is not None:\n",
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" key = key_or_tuple\n",
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" else:\n",
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" raise TypeError(\"Invalid arguments: insert() takes either a tuple or a key-value pair\")\n",
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" self._kvstore.append((key, value))\n",
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" self._kvstore.sort()\n",
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" \n",
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" \n",
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" @abstractmethod\n",
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" def is_leaf(self):\n",
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" pass"
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]
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},
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{
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"cell_type": "code",
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"execution_count": 10,
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"id": "cardiac-techno",
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"metadata": {},
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"outputs": [],
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"source": [
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"class BPlusTreeInternalNode(BPlusTreeNode):\n",
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" def __init__(self):\n",
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" super().__init__()\n",
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" \n",
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" def is_leaf(self):\n",
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" return False\n",
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"\n",
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"#############\n",
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"### Tests ###\n",
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"#############\n",
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"node = BPlusTreeInternalNode()\n",
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"node1 = BPlusTreeInternalNode()\n",
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"node2 = BPlusTreeInternalNode()\n",
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"node3 = BPlusTreeInternalNode()\n",
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"node4 = BPlusTreeInternalNode()\n",
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"\n",
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"node.insert(20, node1)\n",
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"node.insert(10, node2)\n",
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"node.insert((30, node3))\n",
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"node.insert(2, node4)\n",
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"assert node._kvstore == [(2, node4), (10, node2), (20, node1), (30, node3)]\n",
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"assert node.order() == 4\n",
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"assert node.find(10) == (10, node2)\n",
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"assert not node.is_leaf()\n",
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"node.delete(2)\n",
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"assert node._kvstore == [(10, node2), (20, node1), (30, node3)]"
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]
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},
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{
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"cell_type": "code",
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"execution_count": 13,
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"id": "instructional-final",
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"metadata": {},
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"outputs": [],
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"source": [
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"class BPlusTreeLeafNode(BPlusTreeNode):\n",
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" def __init__(self, next_leaf = None, prev_leaf = None):\n",
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" super().__init__()\n",
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" self._next_leaf = next_leaf\n",
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" self._prev_leaf = prev_leaf\n",
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"\n",
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" def insert(self, key_or_tuple, value=None):\n",
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" if isinstance(key_or_tuple, tuple) and value is None:\n",
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" key, value = key_or_tuple\n",
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" elif not isinstance(key_or_tuple, tuple) and value is not None:\n",
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" key = key_or_tuple\n",
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" else:\n",
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" raise TypeError(\"Invalid arguments: insert() takes either a tuple or a key-value pair\")\n",
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" self._kvstore.append((key, value))\n",
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" self._kvstore.sort()\n",
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" \n",
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" def is_leaf(self):\n",
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" return True\n",
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" \n",
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" def set_next_leaf(self, next_leaf):\n",
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" self._next_leaf = next_leaf\n",
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" \n",
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" def get_next_leaf(self):\n",
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" return self._next_leaf\n",
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"\n",
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" def set_prev_leaf(self, prev_leaf):\n",
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" self._prev_leaf = prev_leaf\n",
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" \n",
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" def get_prev_leaf(self):\n",
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" return self._prev_leaf\n",
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"\n",
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"\n",
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"#############\n",
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"### Tests ###\n",
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"#############\n",
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"node = BPlusTreeLeafNode()\n",
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"node.insert(20, \"bob\")\n",
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"node.insert(10, \"alice\")\n",
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"node.insert((30, \"cathy\"))\n",
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"node.insert(2, \"doug\")\n",
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"assert node._kvstore == [(2, 'doug'), (10, 'alice'), (20, 'bob'), (30, 'cathy')]\n",
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"assert node.order() == 4\n",
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"assert node.find(10) == (10, 'alice')\n",
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"assert node.is_leaf()\n",
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"node.delete(2)\n",
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"assert node._kvstore == [(10, 'alice'), (20, 'bob'), (30, 'cathy')]\n",
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"\n",
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"node0 = BPlusTreeLeafNode()\n",
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"for i in range(10):\n",
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" node0.insert((i, f\"boomer{i}\"))\n",
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"node2 = BPlusTreeLeafNode()\n",
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"for i in range(10):\n",
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" node2.insert((i, f\"coomer{i}\"))\n",
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"\n",
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"node.set_prev_leaf(node0)\n",
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"assert node.get_prev_leaf() == node0\n",
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"node.set_next_leaf(node2)\n",
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"assert node.get_next_leaf() == node2\n"
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]
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},
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{
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"cell_type": "code",
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"execution_count": 46,
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"id": "rotary-storage",
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"metadata": {},
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"outputs": [],
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"source": [
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"class BPlusTree:\n",
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" \"\"\"\n",
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" B-tree, but with some constraints:\n",
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" - Keys can only be stored in leaf nodes\n",
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" - All nodes but root must be half-full to maintain balance\n",
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" - Leaf nodes connected via pointers (for traverse())\n",
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" - All records stored in leaf nodes\n",
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" \"\"\"\n",
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" def __init__(self, order, root = None):\n",
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" self._root = BTreeNode() if root == None else root\n",
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" self._order = order\n",
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" \n",
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" def insert(self, key):\n",
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" pass\n",
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" \n",
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" def delete(self, key):\n",
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" pass\n",
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" \n",
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" def find(self, key):\n",
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" pass\n",
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" \n",
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" def traverse(self):\n",
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" pass\n",
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" \n",
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" def range_query(self, start_key, end_key):\n",
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" pass\n",
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" \n",
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" def load(self):\n",
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" pass\n",
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"\n",
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"#############\n",
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"### Tests ###\n",
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"#############\n"
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]
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}
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],
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"metadata": {
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"kernelspec": {
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"display_name": "Python 3",
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"language": "python",
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"name": "python3"
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},
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"language_info": {
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"codemirror_mode": {
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"name": "ipython",
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"version": 3
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},
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"file_extension": ".py",
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"mimetype": "text/x-python",
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"name": "python",
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"nbconvert_exporter": "python",
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"pygments_lexer": "ipython3",
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"version": "3.9.16"
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}
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},
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"nbformat": 4,
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"nbformat_minor": 5
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}

‎notebooks/Math.ipynb

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"## References / Credits\n",
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"- [CS 97 maths](https://web.stanford.edu/class/cs97si/02-mathematics.pdf)"
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]
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},
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{
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"cell_type": "code",
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"execution_count": 9,
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"id": "5b16487f",
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"metadata": {},
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"outputs": [
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{
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"data": {
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"text/plain": [
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"True"
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]
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},
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"execution_count": 9,
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"metadata": {},
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"output_type": "execute_result"
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}
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],
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"source": [
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"(2**8) == ((2**4)**2)"
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]
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},
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{
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"cell_type": "code",
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"execution_count": 47,
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"id": "ff7e211d",
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"metadata": {},
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"outputs": [
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{
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"name": "stdout",
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"output_type": "stream",
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"text": [
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"0.3333333333333333\n"
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]
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}
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],
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"source": [
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"print(1/3)"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"id": "c73abfa1",
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"metadata": {},
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"outputs": [],
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"source": []
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}
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],
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"metadata": {

‎notebooks/WIP/Binary Search Tree.ipynb

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],
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"metadata": {
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"kernelspec": {
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"display_name": "Python 3 (ipykernel)",
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"display_name": "Python 3",
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"language": "python",
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"name": "python3"
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},
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"name": "python",
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"nbconvert_exporter": "python",
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"pygments_lexer": "ipython3",
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"version": "3.8.10"
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"version": "3.9.16"
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}
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},
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"nbformat": 4,

‎notebooks/WIP/Contents.ipynb

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],
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"metadata": {
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"kernelspec": {
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"display_name": "Python 3 (ipykernel)",
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"display_name": "Python 3",
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"language": "python",
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"name": "python3"
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},
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"name": "python",
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"nbconvert_exporter": "python",
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"pygments_lexer": "ipython3",
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"version": "3.10.4"
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"version": "3.9.16"
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}
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},
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"nbformat": 4,

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