Merge pull request akshitagit#95 from jeremie-gauthier/feat/binary-tree

akshitagupta15june · web-flow · commit 4d00942a85b8 · 2020-10-19T00:46:15.000+05:30
add binary tree structure
diff --git a/DataStructures/BinaryTree.js b/DataStructures/BinaryTree.js
@@ -0,0 +1,91 @@
+class Node {
+	constructor(data) {
+		this.data = data;
+		this.left = null;
+		this.right = null;
+	}
+}
+
+class BinaryTree {
+	constructor() {
+		this.root = null;
+	}
+
+	insert(data) {
+		const newNode = new Node(data);
+
+		if (this.root === null) {
+			this.root = newNode;
+		} else {
+			this.insertNode(this.root, newNode);
+		}
+	}
+
+	insertNode(node, newNode) {
+		if (newNode.data < node.data) {
+			if (node.left === null) {
+				node.left = newNode;
+			} else {
+				this.insertNode(node.left, newNode);
+			}
+		} else {
+			if (node.right === null) {
+				node.right = newNode;
+			} else {
+				this.insertNode(node.right, newNode);
+			}
+		}
+	}
+
+	remove(data) {
+		this.root = this.removeNode(this.root, data);
+	}
+
+	removeNode(node, key) {
+		if (node === null) {
+			return null;
+		} else if (key < node.data) {
+			node.left = this.removeNode(node.left, key);
+		} else if (key > node.data) {
+			node.right = this.removeNode(node.right, key);
+		} else {
+			if (node.left === null && node.right === null) {
+				node = null;
+			} else if (node.left === null) {
+				node = node.right;
+			} else if (node.right === null) {
+				node = node.left;
+			} else {
+				const childRight = node.right;
+
+				this.insertNode(childRight, node.left);
+				node = childRight;
+			}
+		}
+		return node;
+	}
+
+	preorder(fn, node = this.root) {
+		if (node !== null) {
+			fn(node);
+			this.preorder(fn, node.left);
+			this.preorder(fn, node.right);
+		}
+	}
+
+	inorder(fn, node = this.root) {
+		if (node !== null) {
+			this.preorder(fn, node.left);
+			fn(node);
+			this.preorder(fn, node.right);
+		}
+	}
+
+	postorder(fn, node = this.root) {
+		if (node !== null) {
+			this.preorder(fn, node.left);
+			this.preorder(fn, node.right);
+			fn(node);
+		}
+	}
+}
