Iterative searching in Binary Search Tree
Given a binary search tree and a key. Check the given key exists in BST or not without recursion.
Please refer binary search tree insertion for recursive search.
C++
// C++ program to demonstrate searching operation// in binary search tree without recursion#include <bits/stdc++.h>using namespace std;struct Node { int data; struct Node *left, *right;};// Function to check the given key exist or notbool iterativeSearch(struct Node* root, int key){ // Traverse until root reaches to dead end while (root != NULL) { // pass right subtree as new tree if (key > root->data) root = root->right; // pass left subtree as new tree else if (key < root->data) root = root->left; else return true; // if the key is found return 1 } return false;}// A utility function to create a new BST Nodestruct Node* newNode(int item){ struct Node* temp = new Node; temp->data = item; temp->left = temp->right = NULL; return temp;}/* A utility function to insert a new Node with given key in BST */struct Node* insert(struct Node* Node, int data){ /* If the tree is empty, return a new Node */ if (Node == NULL) return newNode(data); /* Otherwise, recur down the tree */ if (data < Node->data) Node->left = insert(Node->left, data); else if (data > Node->data) Node->right = insert(Node->right, data); /* return the (unchanged) Node pointer */ return Node;}// Driver Program to test above functionsint main(){ /* Let us create following BST 50 / \ 30 70 / \ / \ 20 40 60 80 */ struct Node* root = NULL; root = insert(root, 50); insert(root, 30); insert(root, 20); insert(root, 40); insert(root, 70); insert(root, 60); insert(root, 80); if (iterativeSearch(root, 15)) cout << "Yes"; else cout << "No"; return 0;} |
Java
// Java program to demonstrate searching operation// in binary search tree without recursionimport java.util.*;class GFG { static class Node { int data; Node left, right; }; // Function to check the given key exist or not static boolean iterativeSearch(Node root, int key) { // Traverse until root reaches to dead end while (root != null) { // pass right subtree as new tree if (key > root.data) root = root.right; // pass left subtree as new tree else if (key < root.data) root = root.left; else return true; // if the key is found return 1 } return false; } // A utility function to create a new BST Node static Node newNode(int item) { Node temp = new Node(); temp.data = item; temp.left = temp.right = null; return temp; } /* A utility function to insert a new Node with given key in BST */ static Node insert(Node Node, int data) { /* If the tree is empty, return a new Node */ if (Node == null) return newNode(data); /* Otherwise, recur down the tree */ if (data < Node.data) Node.left = insert(Node.left, data); else if (data > Node.data) Node.right = insert(Node.right, data); /* return the (unchanged) Node pointer */ return Node; } // Driver code public static void main(String args[]) { /* Let us create following BST 50 / \ 30 70 / \ / \ 20 40 60 80 */ Node root = null; root = insert(root, 50); insert(root, 30); insert(root, 20); insert(root, 40); insert(root, 70); insert(root, 60); insert(root, 80); if (iterativeSearch(root, 15)) System.out.println("YES"); else System.out.println("NO"); }}// This code is contributed by Arnab Kundu |
Python3
# Python program to demonstrate searching operation # in binary search tree without recursionclass newNode: # Constructor to create a new node def __init__(self, data): self.data = data self.left = None self.right = None# Function to check the given # key exist or not def iterativeSearch(root, key): # Traverse until root reaches # to dead end while root != None: # pass right subtree as new tree if key > root.data: root = root.right # pass left subtree as new tree elif key < root.data: root = root.left else: return True # if the key is found return 1 return False# A utility function to insert a # new Node with given key in BST def insert(Node, data): # If the tree is empty, return # a new Node if Node == None: return newNode(data) # Otherwise, recur down the tree if data < Node.data: Node.left = insert(Node.left, data) elif data > Node.data: Node.right = insert(Node.right, data) # return the (unchanged) Node pointer return Node# Driver Codeif __name__ == '__main__': # Let us create following BST # 50 # 30 70 # / \ / \ # 20 40 60 80 root = None root = insert(root, 50) insert(root, 30) insert(root, 20) insert(root, 40) insert(root, 70) insert(root, 60) insert(root, 80) if iterativeSearch(root, 15): print("Yes") else: print("No") # This code is contributed by PranchalK |
C#
// C# program to demonstrate searching operation// in binary search tree without recursionusing System;class GFG { public class Node { public int data; public Node left, right; }; // Function to check the given key exist or not static bool iterativeSearch(Node root, int key) { // Traverse until root reaches to dead end while (root != null) { // pass right subtree as new tree if (key > root.data) root = root.right; // pass left subtree as new tree else if (key < root.data) root = root.left; else return true; // if the key is found return 1 } return false; } // A utility function to create a new BST Node static Node newNode(int item) { Node temp = new Node(); temp.data = item; temp.left = temp.right = null; return temp; } /* A utility function to insert a new Node with given key in BST */ static Node insert(Node Node, int data) { /* If the tree is empty, return a new Node */ if (Node == null) return newNode(data); /* Otherwise, recur down the tree */ if (data < Node.data) Node.left = insert(Node.left, data); else if (data > Node.data) Node.right = insert(Node.right, data); /* return the (unchanged) Node pointer */ return Node; } // Driver code public static void Main(String[] args) { /* Let us create following BST 50 / \ 30 70 / \ / \ 20 40 60 80 */ Node root = null; root = insert(root, 50); insert(root, 30); insert(root, 20); insert(root, 40); insert(root, 70); insert(root, 60); insert(root, 80); if (iterativeSearch(root, 15)) Console.WriteLine("YES"); else Console.WriteLine("NO"); }}// This code has been contributed by 29AjayKumar |
Javascript
<script>// JavaScript program to // demonstrate searching operation// in binary search tree without recursionclass Node { constructor() { this.data = 0; this.left = null; this.right = null; }} // Function to check the given key exist or not function iterativeSearch(root , key) { // Traverse until root reaches to dead end while (root != null) { // pass right subtree as new tree if (key > root.data) root = root.right; // pass left subtree as new tree else if (key < root.data) root = root.left; else // if the key is found return 1 return true; } return false; } // A utility function to create a new BST Node function newNode(item) { var temp = new Node(); temp.data = item; temp.left = temp.right = null; return temp; } /* A utility function to insert a new Node with given key in BST */ function insert(Node , data) { /* If the tree is empty, return a new Node */ if (Node== null) return newNode(data); /* Otherwise, recur down the tree */ if (data < Node.data) Node.left = insert(Node.left, data); else if (data > Node.data) Node.right = insert(Node.right, data); /* return the (unchanged) Node pointer */ return Node; } // Driver code /* Let us create following BST 50 / \ 30 70 / \ / \ 20 40 60 80 */ var root = null; root = insert(root, 50); insert(root, 30); insert(root, 20); insert(root, 40); insert(root, 70); insert(root, 60); insert(root, 80); if (iterativeSearch(root, 15)) document.write("YES"); else document.write("NO"); // This code is contributed by todaysgaurav</script> |
Output
No
Time Complexity: O(h), here h is the height of the BST.
Auxiliary Space: O(1), as constant extra space is used.
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