Update find-the-minimum-and-maximum-value-in-a-binary-search-tree.english.md (#35057)
Added solution which has been tested and confirmed to pass all tests
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@ -108,6 +108,176 @@ BinarySearchTree.prototype = {
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<section id='solution'>
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```js
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// solution required
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var displayTree = tree => console.log(JSON.stringify(tree, null, 2));
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function Node(value) {
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this.value = value;
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this.left = null;
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this.right = null;
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}
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function BinarySearchTree() {
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this.root = null;
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this.findMin = function() {
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// Empty tree.
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if (!this.root) {
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return null;
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}
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let currentNode = this.root;
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while (currentNode.left) {
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currentNode = currentNode.left;
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}
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return currentNode.value;
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};
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this.findMax = function() {
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// Empty tree.
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if (!this.root) {
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return null;
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}
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let currentNode = this.root;
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while (currentNode.right) {
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currentNode = currentNode.right;
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}
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return currentNode.value;
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};
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this.add = function(value) {
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// Empty tree.
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if (!this.root) {
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this.root = new Node(value);
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return undefined;
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}
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return this.addNode(this.root, value);
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};
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this.addNode = function(node, value) {
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// Check if value already exists.
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if (node.value === value) return null;
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if (value < node.value) {
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if (node.left) {
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return this.addNode(node.left, value);
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} else {
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node.left = new Node(value);
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return undefined;
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}
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} else {
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if (node.right) {
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return this.addNode(node.right, value);
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} else {
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node.right = new Node(value);
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return undefined;
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}
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}
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};
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this.isPresent = function(value) {
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if (!this.root) {
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return null;
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}
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return this.isNodePresent(this.root, value);
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};
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this.isNodePresent = function(node, value) {
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if (node.value === value) return true;
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if (value < node.value) {
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return node.left ? this.isNodePresent(node.left, value) : false;
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} else {
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return node.right ? this.isNodePresent(node.right, value) : false;
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}
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return false;
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};
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this.findMinHeight = function() {
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if (!this.root) {
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return -1;
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}
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let heights = {};
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let height = 0;
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this.traverseTree(this.root, height, heights);
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return Math.min(...Object.keys(heights));
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};
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this.findMaxHeight = function() {
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if (!this.root) {
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return -1;
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}
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let heights = {};
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let height = 0;
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this.traverseTree(this.root, height, heights);
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return Math.max(...Object.keys(heights));
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};
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this.traverseTree = function(node, height, heights) {
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if (node.left === null && node.right === null) {
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return (heights[height] = true);
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}
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if (node.left) {
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this.traverseTree(node.left, height + 1, heights);
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}
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if (node.right) {
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this.traverseTree(node.right, height + 1, heights);
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}
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};
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this.isBalanced = function() {
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return this.findMaxHeight() > this.findMinHeight() + 1;
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};
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// DFS tree traversal.
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this.inorder = function() {
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if (!this.root) return null;
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let result = [];
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function traverseInOrder(node) {
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if (node.left) traverseInOrder(node.left);
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result.push(node.value);
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if (node.right) traverseInOrder(node.right);
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}
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traverseInOrder(this.root);
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return result;
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};
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this.preorder = function() {
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if (!this.root) return null;
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let result = [];
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function traverseInOrder(node) {
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result.push(node.value);
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if (node.left) traverseInOrder(node.left);
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if (node.right) traverseInOrder(node.right);
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}
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traverseInOrder(this.root);
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return result;
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};
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this.postorder = function() {
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if (!this.root) return null;
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let result = [];
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function traverseInOrder(node) {
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if (node.left) traverseInOrder(node.left);
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if (node.right) traverseInOrder(node.right);
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result.push(node.value);
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}
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traverseInOrder(this.root);
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return result;
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};
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// BFS tree traversal.
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this.levelOrder = function() {
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if (!this.root) return null;
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let queue = [this.root];
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let result = [];
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while (queue.length) {
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let node = queue.shift();
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result.push(node.value);
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if (node.left) queue.push(node.left);
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if (node.right) queue.push(node.right);
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}
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return result;
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};
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this.reverseLevelOrder = function() {
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if (!this.root) return null;
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let queue = [this.root];
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let result = [];
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while (queue.length) {
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let node = queue.shift();
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result.push(node.value);
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if (node.right) queue.push(node.right);
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if (node.left) queue.push(node.left);
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}
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return result;
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};
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// Delete a leaf node.
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}
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let bst = new BinarySearchTree();
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```
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</section>
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