4.9 KiB
4.9 KiB
id | title | challengeType |
---|---|---|
587d8258367417b2b2512c80 | Delete a Leaf Node in a Binary Search Tree | 1 |
Description
remove
. We'll build the logic for our deletion operation in here. First, you'll want to create a function within remove that finds the node we are trying to delete in the current tree. If the node is not present in the tree, remove
should return null
. Now, if the target node is a leaf node with no children, then the parent reference to it should be set to null
. This effectively deletes the node from the tree. To do this, you will have to keep track of the parent of the node we are trying to delete as well. It will also be useful to create a way to track the number of children the target node has, as this will determine which case our deletion falls under.
We will handle the second and third cases in the next challenges. Good luck!
Instructions
Tests
tests:
- text: The <code>BinarySearchTree</code> data structure exists.
testString: 'assert((function() { var test = false; if (typeof BinarySearchTree !== "undefined") { test = new BinarySearchTree() }; return (typeof test == "object")})(), "The <code>BinarySearchTree</code> data structure exists.");'
- text: The binary search tree has a method called <code>remove</code>.
testString: 'assert((function() { var test = false; if (typeof BinarySearchTree !== "undefined") { test = new BinarySearchTree() } else { return false; }; return (typeof test.remove == "function")})(), "The binary search tree has a method called <code>remove</code>.");'
- text: Trying to remove an element that does not exist returns <code>null</code>.
testString: 'assert((function() { var test = false; if (typeof BinarySearchTree !== "undefined") { test = new BinarySearchTree() } else { return false; }; if (typeof test.remove !== "function") { return false; }; return (test.remove(100) == null); })(), "Trying to remove an element that does not exist returns <code>null</code>.");'
- text: 'If the root node has no children, deleting it sets the root to <code>null</code>.'
testString: 'assert((function() { var test = false; if (typeof BinarySearchTree !== "undefined") { test = new BinarySearchTree() } else { return false; }; if (typeof test.remove !== "function") { return false; }; test.add(500); test.remove(500); return (test.inorder() == null); })(), "If the root node has no children, deleting it sets the root to <code>null</code>.");'
- text: The <code>remove</code> method removes leaf nodes from the tree
testString: 'assert((function() { var test = false; if (typeof BinarySearchTree !== "undefined") { test = new BinarySearchTree() } else { return false; }; if (typeof test.remove !== "function") { return false; }; test.add(5); test.add(3); test.add(7); test.add(6); test.add(10); test.add(12); test.remove(3); test.remove(12); test.remove(10); return (test.inorder().join("") == "567"); })(), "The <code>remove</code> method removes leaf nodes from the tree");'
Challenge Seed
var displayTree = (tree) => console.log(JSON.stringify(tree, null, 2));
function Node(value) {
this.value = value;
this.left = null;
this.right = null;
}
function BinarySearchTree() {
this.root = null;
// case 1: target has no children, change code below this line
}
After Test
console.info('after the test');
Solution
// solution required