Kth Ancestor in a Tree.cpp

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

struct Node
{
    int data;
    struct Node *left;
    struct Node *right;
};
Node *newNode(int val)
{
    Node *temp = new Node;
    temp->data = val;
    temp->left = NULL;
    temp->right = NULL;

    return temp;
}
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 = newNode(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 = newNode(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 = newNode(stoi(currVal));

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

    return root;
}
int kthAncestor(Node *root, int k, int node);

int main()
{
    int t;
    scanf("%d ", &t);
    while (t--)
    {
        int k, node;
        scanf("%d ", &k);
        scanf("%d ", &node);
        string s;
        getline(cin, s);
        Node *root = buildTree(s);
        cout << kthAncestor(root, k, node) << endl;
    }
    return 0;
}

// } Driver Code Ends

// User function Template for C++
/*
Structure of the node of the binary tree is as
struct Node
{
    int data;
    struct Node *left, *right;
};
*/
// your task is to complete this function
bool solve(Node *root, int &cnt, int &node, int &val)
{
    if (root == NULL)
        return 0;

    if (root->data == node)
    {
        return 1;
    }
    int l = solve(root->left, cnt, node, val);

    int r = solve(root->right, cnt, node, val);

    if (l || r)
    {
        cnt--;
        if (cnt == 0)
            val = root->data;

        return 1;
    }

    return 0;
}

int kthAncestor(Node *root, int k, int node)
{

    int cnt = k;
    int val = -1;

    solve(root, cnt, node, val);

    return val;
}