Is_this_a_BST.c

/* Hidden stub code will pass a root argument to the function below. Complete the function to solve the challenge. Hint: you may want to write one or more helper functions.  

The Node struct is defined as follows:
	struct Node {
		int data;
		Node* left;
		Node* right;
	}
*/
#include <climits>
bool isBST(Node *root, int min, int max){
    if(root==NULL)
        return true;
    else
    {
        if(root->data < min || root->data > max)
            return false;
        else{
            return isBST(root->left, min, root->data - 1) && isBST(root->right, root->data + 1, max);
        }
    }
}
	bool checkBST(Node* root) {
        return isBST(root, INT_MIN, INT_MAX);	
	}