# Is This a Binary Search Tree?

### Problem Statement :

```For the purposes of this challenge, we define a binary tree to be a binary search tree with the following ordering requirements:

The data value of every node in a node's left subtree is less than the data value of that node.
The data value of every node in a node's right subtree is greater than the data value of that node.
Given the root node of a binary tree, can you determine if it's also a binary search tree?

Complete the function in your editor below, which has 1 parameter: a pointer to the root of a binary tree. It must return a boolean denoting whether or not the binary tree is a binary search tree. You may have to write one or more helper functions to complete this challenge.

Input Format

You are not responsible for reading any input from stdin. Hidden code stubs will assemble a binary tree and pass its root node to your function as an argument.

Constraints

0 <= data <= 10^4

Output Format

You are not responsible for printing any output to stdout. Your function must return true if the tree is a binary search tree; otherwise, it must return false. Hidden code stubs will print this result as a Yes or No answer on a new line.```

### Solution :

```                            ```Solution in C :

In C ++ :

The Node struct is defined as follows:
struct Node {
int data;
Node* left;
Node* right;
}
*/  enum comp {LESS, GREATER};
bool checkBST(Node* root,int minVal, int maxVal ){
if(root==0)
return true;
int nVal=root->data;
if(nVal<=minVal || nVal>=maxVal)
return false;
return checkBST(root->left,minVal,nVal) && checkBST(root->right,nVal, maxVal);
}
bool checkBST(Node* root) {
if(root==0)
return true;
return checkBST(root->left, -1, root->data) && checkBST(root->right,root->data, 10001);
}

In Java :

The Node class is defined as follows:
class Node {
int data;
Node left;
Node right;
}
*/
private boolean checkBST(Node n, int min, int max) {
if(n == null) return true;
return n.data > min && n.data < max && checkBST(n.left, min, n.data) && checkBST(n.right, n.data, max);
}

boolean checkBST(Node root) {
if(root == null) return true;
if(count == 0) return true;
return checkBST(root, Integer.MIN_VALUE, Integer.MAX_VALUE);
}

In  python3 :

from collections import deque
""" Node is defined as
class node:
def __init__(self, data):
self.data = data
self.left = None
self.right = None
"""
def check_binary_search_tree_(root, lowest_value=0, highest_value=10000):
min_v = lowest_value - 1
max_v = highest_value + 1
q = deque([(root, min_v, max_v)])
while q:
node, min_val, max_val = q.popleft()
if not node: continue
if node.data >= max_val or node.data <= min_val: return False
if node.left: q.append((node.left, min_val, node.data))
if node.right: q.append((node.right, node.data, max_val))
return True```
```

## Tree: Preorder Traversal

Complete the preorder function in the editor below, which has 1 parameter: a pointer to the root of a binary tree. It must print the values in the tree's preorder traversal as a single line of space-separated values. Input Format Our test code passes the root node of a binary tree to the preOrder function. Constraints 1 <= Nodes in the tree <= 500 Output Format Print the tree's

## Tree: Postorder Traversal

Complete the postorder function in the editor below. It received 1 parameter: a pointer to the root of a binary tree. It must print the values in the tree's postorder traversal as a single line of space-separated values. Input Format Our test code passes the root node of a binary tree to the postorder function. Constraints 1 <= Nodes in the tree <= 500 Output Format Print the

## Tree: Inorder Traversal

In this challenge, you are required to implement inorder traversal of a tree. Complete the inorder function in your editor below, which has 1 parameter: a pointer to the root of a binary tree. It must print the values in the tree's inorder traversal as a single line of space-separated values. Input Format Our hidden tester code passes the root node of a binary tree to your \$inOrder* func

## Tree: Height of a Binary Tree

The height of a binary tree is the number of edges between the tree's root and its furthest leaf. For example, the following binary tree is of height : image Function Description Complete the getHeight or height function in the editor. It must return the height of a binary tree as an integer. getHeight or height has the following parameter(s): root: a reference to the root of a binary

## Tree : Top View

Given a pointer to the root of a binary tree, print the top view of the binary tree. The tree as seen from the top the nodes, is called the top view of the tree. For example : 1 \ 2 \ 5 / \ 3 6 \ 4 Top View : 1 -> 2 -> 5 -> 6 Complete the function topView and print the resulting values on a single line separated by space.

## Tree: Level Order Traversal

Given a pointer to the root of a binary tree, you need to print the level order traversal of this tree. In level-order traversal, nodes are visited level by level from left to right. Complete the function levelOrder and print the values in a single line separated by a space. For example: 1 \ 2 \ 5 / \ 3 6 \ 4 F