Refactored linked list class. Class is now loaded by other notebooks that reference it.

This commit is contained in:
Donne Martin 2015-05-13 06:39:16 -04:00
parent 6f3e3b0b8f
commit 4c1f87a2ae
3 changed files with 80 additions and 122 deletions

View File

@ -19,8 +19,6 @@
"source": [ "source": [
"## Clarifying Questions\n", "## Clarifying Questions\n",
"\n", "\n",
"* Do we assume the linked list class already exists?\n",
" * No, create one\n",
"* What if the final node is being deleted, for example a single node list?\n", "* What if the final node is being deleted, for example a single node list?\n",
" * Make it a dummy node" " * Make it a dummy node"
] ]
@ -61,6 +59,17 @@
"## Code" "## Code"
] ]
}, },
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"%run linked_list.py"
]
},
{ {
"cell_type": "code", "cell_type": "code",
"execution_count": null, "execution_count": null,
@ -74,10 +83,7 @@
" self.data = data\n", " self.data = data\n",
" self.next = None\n", " self.next = None\n",
"\n", "\n",
"class LinkedList(object):\n", "class MyLinkedList(LinkedList):\n",
" def __init__(self, head):\n",
" self.head = head\n",
" \n",
" def delete_node(self, node):\n", " def delete_node(self, node):\n",
" if self.head is None:\n", " if self.head is None:\n",
" return\n", " return\n",
@ -89,25 +95,7 @@
" node.next = None\n", " node.next = None\n",
" else:\n", " else:\n",
" node.data = next.data\n", " node.data = next.data\n",
" node.next = next.next\n", " node.next = next.next"
"\n",
" \n",
" def insert_to_front(self, data):\n",
" if data is None:\n",
" return\n",
" node = Node(data)\n",
" if self.head is None:\n",
" self.head = node\n",
" else:\n",
" node.next = self.head\n",
" self.head = node\n",
" return node\n",
" \n",
" def print_list(self):\n",
" curr_node = self.head\n",
" while curr_node is not None:\n",
" print(curr_node.data)\n",
" curr_node = curr_node.next"
] ]
}, },
{ {

View File

@ -18,17 +18,13 @@
"source": [ "source": [
"## Clarifying Questions\n", "## Clarifying Questions\n",
"\n", "\n",
"* Do we assume the linked list class already exists?\n",
" * No, create one\n",
"* Is k an integer?\n", "* Is k an integer?\n",
" * Yes\n", " * Yes\n",
"* If k = 0, does this return the last element?\n", "* If k = 0, does this return the last element?\n",
" * Yes\n", " * Yes\n",
"* What happens if k is greater than or equal to the length of the linked list?\n", "* What happens if k is greater than or equal to the length of the linked list?\n",
" * Return None\n", " * Return None\n",
"* Can you insert NULL values in the list?\n", "* Can you use additional data structures?\n",
" * No\n",
"* Can use additional data structures?\n",
" * No" " * No"
] ]
}, },
@ -69,6 +65,17 @@
"## Code" "## Code"
] ]
}, },
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"%run linked_list.py"
]
},
{ {
"cell_type": "code", "cell_type": "code",
"execution_count": null, "execution_count": null,
@ -77,28 +84,12 @@
}, },
"outputs": [], "outputs": [],
"source": [ "source": [
"class Node(object):\n", "class MyLinkedList(LinkedList):\n",
" def __init__(self, data):\n",
" self.data = data\n",
" self.next = None\n",
" \n",
"class LinkedList(object):\n",
" def __init__(self, head):\n",
" self.head = head\n",
" \n",
" def __len__(self):\n",
" curr = self.head\n",
" counter = 0\n",
" while curr is not None:\n",
" counter += 1\n",
" curr = curr.next\n",
" return counter\n",
" \n",
" def kth_to_last_elem(self, k):\n", " def kth_to_last_elem(self, k):\n",
" if self.head is None:\n", " if self.head is None:\n",
" return\n", " return\n",
" if type(k) != int:\n", " if type(k) != int:\n",
" return\n", " raise ValueError('')\n",
" if k >= len(self):\n", " if k >= len(self):\n",
" return\n", " return\n",
" curr = self.head\n", " curr = self.head\n",
@ -112,20 +103,19 @@
" while curr.next is not None:\n", " while curr.next is not None:\n",
" curr = curr.next\n", " curr = curr.next\n",
" prev = prev.next\n", " prev = prev.next\n",
" return prev.data\n", " return prev.data"
" \n", ]
" def insert_to_front(self, data):\n", },
" if data is None:\n", {
" return\n", "cell_type": "code",
" node = Node(data)\n", "execution_count": null,
" if self.head is None:\n", "metadata": {
" self.head = node\n", "collapsed": false
" else:\n", },
" node.next = self.head\n", "outputs": [],
" self.head = node\n", "source": [
" \n",
"# Empty list\n", "# Empty list\n",
"linked_list = LinkedList(None)\n", "linked_list = MyLinkedList(None)\n",
"print(linked_list.kth_to_last_elem(0))\n", "print(linked_list.kth_to_last_elem(0))\n",
"# k is not an integer\n", "# k is not an integer\n",
"print(linked_list.kth_to_last_elem('a'))\n", "print(linked_list.kth_to_last_elem('a'))\n",
@ -133,7 +123,7 @@
"print(linked_list.kth_to_last_elem(100))\n", "print(linked_list.kth_to_last_elem(100))\n",
"# One element, k = 0\n", "# One element, k = 0\n",
"head = Node(2)\n", "head = Node(2)\n",
"linked_list = LinkedList(head)\n", "linked_list = MyLinkedList(head)\n",
"print(linked_list.kth_to_last_elem(0))\n", "print(linked_list.kth_to_last_elem(0))\n",
"# General case with many elements, k < length of linked list\n", "# General case with many elements, k < length of linked list\n",
"linked_list.insert_to_front(1)\n", "linked_list.insert_to_front(1)\n",

View File

@ -20,13 +20,11 @@
"source": [ "source": [
"## Clarifying Questions\n", "## Clarifying Questions\n",
"\n", "\n",
"* Do we assume the linked list class already exists?\n",
" * No, create one\n",
"* Is this a singly or doubly linked list?\n", "* Is this a singly or doubly linked list?\n",
" * Singly\n", " * Singly\n",
"* Can you insert NULL values in the list?\n", "* Can you insert NULL values in the list?\n",
" * No\n", " * No\n",
"* Can use additional data structures?\n", "* Can you use additional data structures?\n",
" * Implement both solutions" " * Implement both solutions"
] ]
}, },
@ -70,6 +68,17 @@
"## Code: Hash Map Lookup" "## Code: Hash Map Lookup"
] ]
}, },
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"%run linked_list.py"
]
},
{ {
"cell_type": "code", "cell_type": "code",
"execution_count": null, "execution_count": null,
@ -78,15 +87,7 @@
}, },
"outputs": [], "outputs": [],
"source": [ "source": [
"class Node(object):\n", "class MyLinkedList(LinkedList):\n",
" def __init__(self, data):\n",
" self.next = None\n",
" self.data = data\n",
"\n",
"class LinkedList(object):\n",
" def __init__(self, head):\n",
" self.head = head\n",
" \n",
" def remove_dupes(self):\n", " def remove_dupes(self):\n",
" seen_data = set()\n", " seen_data = set()\n",
" curr = self.head\n", " curr = self.head\n",
@ -97,31 +98,24 @@
" else:\n", " else:\n",
" seen_data.add(curr.data)\n", " seen_data.add(curr.data)\n",
" prev = curr\n", " prev = curr\n",
" curr = curr.next\n", " curr = curr.next"
" \n", ]
" def insert_to_front(self, data):\n", },
" if data is None:\n", {
" return\n", "cell_type": "code",
" node = Node(data)\n", "execution_count": null,
" if self.head is None:\n", "metadata": {
" self.head = node\n", "collapsed": false
" else:\n", },
" node.next = self.head\n", "outputs": [],
" self.head = node \n", "source": [
" \n",
" def print_list(self):\n",
" curr = self.head\n",
" while curr is not None:\n",
" print(curr.data)\n",
" curr = curr.next\n",
" \n",
"# Empty linked list\n", "# Empty linked list\n",
"linked_list = LinkedList(None)\n", "linked_list = MyLinkedList(None)\n",
"linked_list.remove_dupes()\n", "linked_list.remove_dupes()\n",
"linked_list.print_list()\n", "linked_list.print_list()\n",
"# One element linked list\n", "# One element linked list\n",
"head = Node(2)\n", "head = Node(2)\n",
"linked_list = LinkedList(head)\n", "linked_list = MyLinkedList(head)\n",
"linked_list.remove_dupes()\n", "linked_list.remove_dupes()\n",
"linked_list.print_list()\n", "linked_list.print_list()\n",
"# Multiple elements\n", "# Multiple elements\n",
@ -174,14 +168,7 @@
}, },
"outputs": [], "outputs": [],
"source": [ "source": [
"class Node(object):\n", "class MyLinkedList(LinkedList):\n",
" def __init__(self, data):\n",
" self.next = None\n",
" self.data = data\n",
"\n",
"class LinkedList(object):\n",
" def __init__(self, head):\n",
" self.head = head\n",
" \n", " \n",
" def remove_dupes(self):\n", " def remove_dupes(self):\n",
" curr = self.head\n", " curr = self.head\n",
@ -192,31 +179,24 @@
" runner.next = runner.next.next\n", " runner.next = runner.next.next\n",
" else:\n", " else:\n",
" runner = runner.next\n", " runner = runner.next\n",
" curr = curr.next\n", " curr = curr.next"
" \n", ]
" def insert_to_front(self, data):\n", },
" if data is None:\n", {
" return\n", "cell_type": "code",
" node = Node(data)\n", "execution_count": null,
" if self.head is None:\n", "metadata": {
" self.head = node\n", "collapsed": true
" else:\n", },
" node.next = self.head\n", "outputs": [],
" self.head = node \n", "source": [
" \n",
" def print_list(self):\n",
" curr = self.head\n",
" while curr is not None:\n",
" print(curr.data)\n",
" curr = curr.next\n",
" \n",
"# Empty linked list\n", "# Empty linked list\n",
"linked_list = LinkedList(None)\n", "linked_list = MyLinkedList(None)\n",
"linked_list.remove_dupes()\n", "linked_list.remove_dupes()\n",
"linked_list.print_list()\n", "linked_list.print_list()\n",
"# One element linked list\n", "# One element linked list\n",
"head = Node(2)\n", "head = Node(2)\n",
"linked_list = LinkedList(head)\n", "linked_list = MyLinkedList(head)\n",
"linked_list.remove_dupes()\n", "linked_list.remove_dupes()\n",
"linked_list.print_list()\n", "linked_list.print_list()\n",
"# Multiple elements\n", "# Multiple elements\n",