Root_To_Leaf_Paths.cpp

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


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

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

// 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;
}

Node* inputTree(){
    string treeString;
    getline(cin,treeString);
    Node* root = buildTree(treeString);
    return root;
}
void inorder(Node *root)
{
    if (root == NULL)
       return;
    inorder(root->left);
    cout << root->data << " ";
    inorder(root->right);
}


class Matrix
{
public:
    template <class T>
    static void input(vector<vector<T>> &A,int n,int m)
    {
        for (int i = 0; i < n; i++)
        {
            for (int j = 0; j < m; j++)
            {
                scanf("%d ",&A[i][j]);
            }
        }
    }

    template <class T>
    static void print(vector<vector<T>> &A)
    {
        for (int i = 0; i < A.size(); i++)
        {
            for (int j = 0; j < A[i].size(); j++)
            {
                cout << A[i][j] << " ";
            }
            cout << endl;
        }
    }
};


// } Driver Code Ends
/*

Definition for Binary Tree Node
struct Node
{
    int data;
    struct Node* left;
    struct Node* right;

    Node(int x){
        data = x;
        left = right = NULL;
    }
};
*/

class Solution {
  public:
    void RootToLeaf(Node* root, vector<vector<int>> &ans, vector<int> &a)
    {
        if(!root) return;
        a.push_back(root->data);
        if(root->left == NULL && root->right == NULL) ans.push_back(a);
        RootToLeaf(root->left, ans, a);
        RootToLeaf(root->right, ans, a);
        a.pop_back();
    }
    vector<vector<int>> Paths(Node* root) {
        vector<vector<int>> ans;
        vector<int> a;
        RootToLeaf(root, ans, a);
        return ans;
    }
};


//{ Driver Code Starts.

int main(){
    int t;
    scanf("%d ",&t);
    while(t--){
        
        Node* root = inputTree();
        
        Solution obj;
        vector<vector<int>> res = obj.Paths(root);
        
        Matrix::print(res);
        
    }
}

// } Driver Code Ends