Check for BST

//{ Driver Code Starts
#include <bits/stdc++.h>
using namespace std;
#define MAX_HEIGHT 100000

// Tree Node
struct Node {
    int data;
    Node *left;
    Node *right;

    Node(int val) {
        data = val;
        left = right = NULL;
    }
};




// } Driver Code Ends
class Solution
{
    public:
    //Function to check whether a Binary Tree is BST or not.
    int maxValue(Node* node)
{
    if (node == NULL) {
        return INT16_MIN;
    }
    int value = node->data;
    int leftMax = maxValue(node->left);
    int rightMax = maxValue(node->right);

    return max(value, max(leftMax, rightMax));
}

int minValue(Node* node)
{
    if (node == NULL) {
        return INT16_MAX;
    }
    int value = node->data;
    int leftMax = minValue(node->left);
    int rightMax = minValue(node->right);

    return min(value, min(leftMax, rightMax));
}

bool isBST(Node* node)
{
    if (node == NULL)
        return 1;


    if (node->left != NULL
        && maxValue(node->left) >= node->data)
        return 0;

    if (node->right != NULL
        && minValue(node->right) <= node->data)
        return 0;


    if (!isBST(node->left) || !isBST(node->right))
        return 0;


    return 1;
}


};




//{ Driver Code Starts.

// Function to Build Tree
Node* buildTree(string str)
{
   // Corner Case
   if(str.length() == 0 || str[0] == 'N')
       return NULL;

   // Creating vector of strings from input
   // string after spliting by space
   vector<string> ip;

   istringstream iss(str);
   for(string str; iss >> str; )
       ip.push_back(str);

   // Create the root of the tree
   Node* root = new Node(stoi(ip[0]));

   // Push the root to the queue
   queue<Node*> queue;
   queue.push(root);

   // Starting from the second element
   int i = 1;
   while(!queue.empty() && i < ip.size()) {

       // Get and remove the front of the queue
       Node* currNode = queue.front();
       queue.pop();

       // Get the current node's value from the string
       string currVal = ip[i];

       // If the left child is not null
       if(currVal != "N") {

           // Create the left child for the current node
           currNode->left = new Node(stoi(currVal));

           // Push it to the queue
           queue.push(currNode->left);
       }

       // For the right child
       i++;
       if(i >= ip.size())
           break;
       currVal = ip[i];

       // If the right child is not null
       if(currVal != "N") {

           // Create the right child for the current node
           currNode->right = new Node(stoi(currVal));

           // Push it to the queue
           queue.push(currNode->right);
       }
       i++;
   }

   return root;
}

void inorder(Node *root, vector<int> &v)
{
    if(root==NULL)
        return;

    inorder(root->left, v);
    v.push_back(root->data);
    inorder(root->right, v);
}

int main() {

   int t;
   string tc;
   getline(cin, tc);
   t=stoi(tc);
   while(t--)
   {
    string s;
    getline(cin, s);
    Node* root = buildTree(s);
    Solution ob;
    if(ob.isBST(root))
        cout<<"1\n";

    else
        cout<<"0\n";
   }
   return 0;
}


// } Driver Code Ends
// https://practice.geeksforgeeks.org/problems/check-for-bst/