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

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.

Implementation:

C++

// 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()
{

    // construct 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;
}

Java

// Java program to find product of
// all leaf nodes of binary tree
class GFG
{

// struct binary tree node
static class Node
{
    int data;
    Node left, right;
};

// return new node
static Node newNode(int data)
{
    Node temp = new Node();
    temp.data = data;
    temp.left = temp.right = null;
    return temp;
}

// product
static int prod = 1;

// utility function which calculates
// product of all leaf nodes
static void leafProduct(Node root )
{
    if (root == null)
        return;

    // product root data to prod if
    // root is a leaf node
    if (root.left == null && root.right == null)
        prod *= root.data;

    // propagate recursively in left
    // and right subtree
    leafProduct(root.left);
    leafProduct(root.right);
}

// Driver program
public static void main(String args[])
{

    // construct 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
    prod = 1;
    leafProduct(root);
    System.out.println(prod );
}
}

// This code is contributed by Arnab Kundu

Python

# Python program to find product of
# all leaf nodes of binary tree

# Node class
class Node:

    # Function to initialise the node object
    def __init__(self, data):
        self.data = data # Assign data
        self.next =None

# return new node
def newNode( data) :

    temp = Node(0)
    temp.data = data
    temp.left = temp.right = None
    return temp

# product
prod = 1

# utility function which calculates
# product of all leaf nodes
def leafProduct( root ) :

    global prod
    if (root == None) :
        return

    # product root data to prod if
    # root is a leaf node
    if (root.left == None and root.right == None):
        prod *= root.data

    # propagate recursively in left
    # and right subtree
    leafProduct(root.left)
    leafProduct(root.right)

# Driver program

# construct binary tree
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
prod = 1
leafProduct(root)
print(prod )

# This code is contributed by Arnab Kundu

C#

// C# program to find product of
// all leaf nodes of binary tree
using System;

class GFG
{

// struct binary tree node
public class Node
{
    public int data;
    public Node left, right;
};

// return new node
static Node newNode(int data)
{
    Node temp = new Node();
    temp.data = data;
    temp.left = temp.right = null;
    return temp;
}

// product
static int prod = 1;

// utility function which calculates
// product of all leaf nodes
static void leafProduct(Node root )
{
    if (root == null)
        return;

    // product root data to prod if
    // root is a leaf node
    if (root.left == null && root.right == null)
        prod *= root.data;

    // propagate recursively in left
    // and right subtree
    leafProduct(root.left);
    leafProduct(root.right);
}

// Driver code
public static void Main(String []args)
{

    // construct 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
    prod = 1;
    leafProduct(root);
    Console.WriteLine(prod );
}
}

// This code has been contributed by 29AjayKumar

Javascript

<script>
// javascript program to find product of
// all leaf nodes of binary tree
// struct binary tree node
class Node {
    constructor(val) {
        this.data = val;
        this.left = null;
        this.right = null;
    }
}

    // return new node
    function newNode(data) {
var temp = new Node();
        temp.data = data;
        temp.left = temp.right = null;
        return temp;
    }

    // product
    var prod = 1;

    // utility function which calculates
    // product of all leaf nodes
    function leafProduct(root) {
        if (root == null)
            return;

        // product root data to prod if
        // root is a leaf node
        if (root.left == null && root.right == null)
            prod *= root.data;

        // propagate recursively in left
        // and right subtree
        leafProduct(root.left);
        leafProduct(root.right);
    }

    // Driver program


        // construct binary tree
var 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
        prod = 1;
        leafProduct(root);
        document.write(prod);

// This code contributed by gauravrajput1
</script>

Output

1120

Time Complexity: O(n), where n is the total number of nodes in the tree.