Root to Leaf Paths | binary tree | geeksforgeeks solution

 Root to Leaf Paths

Given a Binary Tree of size N, you need to find all the possible paths from root node to all the leaf node's of the binary tree.

Example 1:

Input:
       1
    /     \
   2       3
Output: 1 2 #1 3 #
Explanation: 
All possible paths:
1->2
1->3

Example 2:

Input:
         10
       /    \
      20    30
     /  \
    40   60
Output: 10 20 40 #10 20 60 #10 30 #

Your Task:
Your task is to complete the function Paths() that takes the root node as an argument and return all the possible path. (All the path are printed '#' separated by the driver's code.)

Note: The return type
cpp: vector
java: ArrayList>
python: list of list

Expected Time Complexity: O(N).
Expected Auxiliary Space: O(H).
Note: H is the height of the tree.

Constraints:
1<=N<=103

Note: The Input/Ouput format and Example given, are used for the system's internal purpose, and should be used by a user for Expected Output only. As it is a function problem, hence a user should not read any input from the stdin/console. The task is to complete the function specified, and not to write the full code.

solution:

void paths(Node * root , vector<int>t ,vector<vector<int>>&r )

    {

         if(root->left == NULL && root->right == NULL)

         { 

             t.push_back(root->data);

           r.push_back(t);

           return;

         }

         

        if(root->left != NULL)

        {   

            t.push_back(root->data);

            paths(root->left, t , r);

            t.pop_back();

        }

        if(root->right != NULL)

        {   

            t.push_back(root->data);

            paths(root->right, t , r);

            t.pop_back();

        }

             

    }

vector<vector<int>> Paths(Node* root)

{

    vector<int>t ;

    vector<vector<int>>r;

    paths(root , t , r);

    return r;

}