Check if a tree is a BST or not

cpp

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int data;
 *     TreeNode *left;
 *     TreeNode *right;
 *      TreeNode(int val) : data(val) , left(nullptr) , right(nullptr) {}
 * };
 **/

class Solution{
	public:
		bool isBST(TreeNode* root){
			//your code goes here
		}
};

java

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int data;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int val) { data = val; left = null, right = null }
 * }
 **/

class Solution {
    public boolean isBST(TreeNode root) {
        //your code goes here
    }
}

python

# Definition for a binary tree node.
# class TreeNode(object):
#     def __init__(self, val=0, left=None, right=None):
#         self.data = val
#         self.left = left
#         self.right = right

class Solution:
    def isBST(self, root):
        #your code goes here

javascript

/**
 * Definition for a binary tree node.
 * class TreeNode {
 *      constructor(val = 0, left = null, right = null){
 *          this.data = val;
 *          this.left = null;
 *          this.right = null;
 *      }
 * }
 **/

class Solution {
    isBST(root) {
        //your code goes here
    }
}

csharp

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     public int data;
 *     public TreeNode left;
 *     public TreeNode right;
 *     public TreeNode(int val=0, TreeNode left=null, TreeNode right=null) {
 *         this.data = val;
 *         this.left = left;
 *         this.right = right;
 *     }
 * }
 */

public class Solution {
   public bool IsBST(TreeNode root) {
        
    }
}

go

/**
 * Definition for a binary tree node.
 * type TreeNode struct {
 *     Data int
 *     Left *TreeNode
 *     Right *TreeNode
 * }
 */

func IsBST(root *TreeNode) bool {
    //your code goes here
}