GitHub/interactive-coding-challenges
1
0
Fork 0
mirror of https://github.com/donnemartin/interactive-coding-challenges synced 2026-01-05 08:58:02 +00:00
Code Issues Packages Projects Releases Wiki Activity

Move bst successor to a class

Browse Source
This commit is contained in:
Donne Martin
2016-08-14 08:23:11 -04:00
parent 857497115a
commit b91b6a437b
3 changed files with 82 additions and 72 deletions
Download Patch File Download Diff File Expand all files Collapse all files

76
graphs_trees/bst_successor/bst_successor_solution.ipynb
View File

@@ -111,29 +111,28 @@
},
"outputs": [],
"source": [
"def left_most_node(node):\n",
" if node is None:\n",
" return None\n",
" if node.left is None:\n",
"class BstSuccessor(object):\n",
"\n",
" def get_next(self, node):\n",
" if node is None:\n",
" raise Exception('Invalid input node')\n",
" if node.right is not None:\n",
" return self._left_most(node.right)\n",
" return self._next_ancestor(node)\n",
"\n",
" def _left_most(self, node):\n",
" if node.left is not None:\n",
" return self._left_most(node.left)\n",
" return node.data\n",
" return left_most_node(node.left)\n",
"\n",
"\n",
"def bst_successor(node):\n",
" if node is None:\n",
" raise Exception('Invalid input node')\n",
" if node.right is not None:\n",
" return left_most_node(node.right)\n",
" else:\n",
" parent = node.parent\n",
" while parent is not None and parent.left is not node:\n",
" node = node.parent\n",
" parent = node.parent\n",
" if parent is None:\n",
" # We reached the root, the original input node\n",
" # must be the largest element in the tree.\n",
" return None\n",
" return parent.data"
" def _next_ancestor(self, node):\n",
" if node.parent is not None:\n",
" if node.parent.data > node.data:\n",
" return node.parent.data\n",
" return self._next_ancestor(node.parent)\n",
" # We reached the root, the original input node\n",
" # must be the largest element in the tree.\n",
" return None"
]
},
{
@@ -168,28 +167,31 @@
"\n",
" @raises(Exception)\n",
" def test_bst_successor_empty(self):\n",
" bst_successor(None)\n",
" bst_successor = BstSuccessor()\n",
" bst_successor.get_next(None)\n",
"\n",
" def test_bst_successor(self):\n",
" nodes = {}\n",
" node = Node(5)\n",
" nodes[5] = node\n",
" nodes[3] = insert(node, 3)\n",
" nodes[8] = insert(node, 8)\n",
" nodes[2] = insert(node, 2)\n",
" nodes[4] = insert(node, 4)\n",
" nodes[6] = insert(node, 6)\n",
" nodes[12] = insert(node, 12)\n",
" nodes[1] = insert(node, 1)\n",
" nodes[7] = insert(node, 7)\n",
" nodes[10] = insert(node, 10)\n",
" nodes[15] = insert(node, 15)\n",
" nodes[9] = insert(node, 9)\n",
" bst = Bst(nodes[5])\n",
" nodes[3] = bst.insert(3)\n",
" nodes[8] = bst.insert(8)\n",
" nodes[2] = bst.insert(2)\n",
" nodes[4] = bst.insert(4)\n",
" nodes[6] = bst.insert(6)\n",
" nodes[12] = bst.insert(12)\n",
" nodes[1] = bst.insert(1)\n",
" nodes[7] = bst.insert(7)\n",
" nodes[10] = bst.insert(10)\n",
" nodes[15] = bst.insert(15)\n",
" nodes[9] = bst.insert(9)\n",
"\n",
" assert_equal(bst_successor(nodes[4]), 5)\n",
" assert_equal(bst_successor(nodes[5]), 6)\n",
" assert_equal(bst_successor(nodes[8]), 9)\n",
" assert_equal(bst_successor(nodes[15]), None)\n",
" bst_successor = BstSuccessor()\n",
" assert_equal(bst_successor.get_next(nodes[4]), 5)\n",
" assert_equal(bst_successor.get_next(nodes[5]), 6)\n",
" assert_equal(bst_successor.get_next(nodes[8]), 9)\n",
" assert_equal(bst_successor.get_next(nodes[15]), None)\n",
"\n",
" print('Success: test_bst_successor')\n",
"\n",