bst

binarySearchTree.js

@@ -0,0 +1,199 @@
+console.clear()
+
+class Node {
+    constructor(value) {
+        this.value = value
+        this.left = null
+        this.right = null
+    }
+}
+
+class BST {
+    constructor() {
+        this.root = null
+    }
+
+    isEmpty() {
+        return this.root === null
+    }
+
+    insertNode(node, root) {
+        if (node.value < root.value) {
+            if (root.left === null) {
+                root.left = node
+            } else {
+                this.insertNode(node, root.left)
+            }
+        } else {
+            if (root.right === null) {
+                root.right = node
+            } else {
+                this.insertNode(node, root.right)
+
+            }
+        }
+    }
+
+    insert(value) {
+        const node = new Node(value)
+        if (this.isEmpty()) {
+            this.root = node
+        } else {
+            this.insertNode(node, this.root)
+        }
+    }
+
+    search(value, root = this.root) {
+        if (root === null) {
+            return false
+        } else {
+            if (value < root.value) {
+                return this.search(value, root.left)
+            } else if (value > root.value) {
+                return this.search(value, root.right)
+
+            } else {
+                return true
+            }
+        }
+    }
+
+    preOrder(root = this.root) {
+        if (root) {
+            console.log(root.value)
+            this.preOrder(root.left)
+            this.preOrder(root.right)
+        }
+    }
+
+    inOrder(root = this.root) {
+        if (root) {
+            this.inOrder(root.left)
+            console.log(root.value)
+            this.inOrder(root.right)
+        }
+    }
+    postOrder(root = this.root) {
+        if (root) {
+            this.postOrder(root.left)
+            this.postOrder(root.right)
+            console.log(root.value)
+        }
+    }
+
+    levelOrder() {
+        const queue = [this.root]
+        while (queue.length !== 0) {
+            const node = queue.shift()
+            console.log(node.value)
+            if (node.left) {
+                queue.push(node.left)
+            }
+            if (node.right) {
+                queue.push(node.right)
+            }
+        }
+    }
+
+    min(root = this.root) {
+        if (root.left) {
+            return this.min(root.left)
+        } else {
+            return root.value
+        }
+    }
+
+    max(root = this.root) {
+        if (root.right) {
+            return this.max(root.right)
+        } else {
+            return root.value
+        }
+    }
+
+    deleteNode(root, value) {
+        if (root === null) {
+            return root
+        }
+        if (root.value === value) {
+            if (!root.left && !root.right) {
+                return null
+            } else if (!root.left) {
+                return root.right
+            } else if (!root.right) {
+                return root.left
+            } else {
+                root.value = this.min(root.right)
+                root.right = this.deleteNode(root.right, root.value)
+            }
+
+        } else if (root.value < value) {
+            root.right = this.deleteNode(root.right, value)
+        } else {
+            root.left = this.deleteNode(root.left, value)
+        }
+
+        return root
+
+
+    }
+
+    delete(value) {
+        if (this.isEmpty()) {
+            return null
+        } else {
+            this.root = this.deleteNode(this.root, value)
+        }
+    }
+
+
+
+}
+
+const bst = new BST()
+console.log(bst.isEmpty())
+
+bst.insert(5)
+bst.insert(3)
+bst.insert(8)
+bst.insert(1)
+bst.insert(4)
+
+
+console.log(bst.search(5))
+
+console.log(bst.search(1))
+
+console.log(bst.search(7))
+
+console.log("===== Pre order ====")
+bst.preOrder()
+console.log("===== In order ====")
+bst.inOrder()
+
+console.log("===== Post order ====")
+bst.postOrder()
+
+
+console.log("===== Level order ====")
+bst.levelOrder()
+
+console.log("Min:", bst.min())
+console.log("Max:", bst.max())
+
+
+bst.insert(7)
+bst.insert(10)
+
+console.log("===== Level order ====")
+bst.levelOrder()
+
+bst.delete(1)
+console.log("===== Level order ====")
+bst.levelOrder()
+
+
+bst.delete(5)
+console.log("===== Level order ====")
+bst.levelOrder()
+