Product of all leaf nodes of binary tree

Given a binary tree, find the product of all the leaf nodes.

Examples:

Input : 
        1
      /   \
     2     3
    / \   / \
   4   5 6   7
          \
           8
Output :
product = 4 * 5 * 8 * 7 = 1120

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

The idea is to traverse the tree in any fashion and check if the node is the leaf node or not. If the node is the leaf node, multiply node data to a variable prod used to store the products of leaf nodes.

Following is the implementation of above approach.

// CPP program to find product of 
// all leaf nodes of binary tree 
#include <bits/stdc++.h> 
using namespace std; 
  
// struct binary tree node 
struct Node { 
    int data; 
    Node *left, *right; 
}; 
  
// return new node 
Node* newNode(int data) 
{ 
    Node* temp = new Node(); 
    temp->data = data; 
    temp->left = temp->right = NULL; 
    return temp; 
} 
  
// utility function which calculates 
// product of all leaf nodes 
void leafProduct(Node* root, int& prod) 
{ 
    if (!root) 
        return; 
  
    // product root data to prod if 
    // root is a leaf node 
    if (!root->left && !root->right) 
        prod *= root->data; 
  
    // propagate recursively in left 
    // and right subtree 
    leafProduct(root->left, prod); 
    leafProduct(root->right, prod); 
} 
  
// Driver program 
int main() 
{ 
  
    // contruct binary tree 
    Node* root = newNode(1); 
    root->left = newNode(2); 
    root->left->left = newNode(4); 
    root->left->right = newNode(5); 
    root->right = newNode(3); 
    root->right->right = newNode(7); 
    root->right->left = newNode(6); 
    root->right->left->right = newNode(8); 
  
    // variable to store product of leaf nodes 
    int prod = 1; 
    leafProduct(root, prod); 
    cout << prod << endl; 
    return 0; 
} 