dubplicateSubTreeInBT.cpp

// { Driver Code Starts
#include <bits/stdc++.h>

using namespace std;

struct Node {
    char data;
    struct Node *left;
    struct Node *right;

    Node(char x) {
        data = x;
        left = NULL;
        right = NULL;
    }
};

struct 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;
}


// } Driver Code Ends
/*The structure of the Binary Tree Node  is
struct Node
{
  char data;
  struct Node* left;
  struct Node* right;
};*/

class Solution {
public:
    /*This function returns true if the tree contains 
    a duplicate subtree of size 2 or more else returns false*/
    void fillMap(Node *root, unordered_map<string , int> &mp) {
        if (root == nullptr) return;
        if (root->left && root->right) {
            string temp;
            temp = to_string(root->data) + "#" + to_string(root->left->data) + "#"  + to_string(root->right->data);
            mp[temp]++;
            cout << mp[temp] << " # " << temp << endl;
        }
        fillMap(root->left, mp);
        fillMap(root->right, mp);
    }

    int dupSub(Node *root) {
        unordered_map<string , int> mp;
        fillMap(root, mp);
        for (auto ele: mp) if (ele.second > 1) return 1;
        return 0;
    }
};

// { Driver Code Starts.

int main() {

    int t;
    cin >> t;
    //cout << t << "\n";
    while (t--) {
        string treeString;
        getline(cin >> ws, treeString);
        struct Node *root = buildTree(treeString);
        Solution ob;
        cout << ob.dupSub(root) << "\n";
    }
    return 0;
}  // } Driver Code Ends