Get Average of all nodes in Binary Tree

Question:

Given a binary tree root node, get the average of all nodes in Binary Tree

Solution:

The sum of all the nodes is 121

Total number of nodes are :7

So the average is 121/7 = 17.2

Solution in C++

#include <iostream>
#include <queue>
#include <stack>
using namespace std;

// structure to hold binary tree node
struct Node
{
    int data;
    Node *left, *right;

    Node(int data)
    {
        this->data = data;
        this->left = this->right = nullptr;
    }
};


int total_sum = 0;
int no_of_nodes = 0;

void get_average(Node *node) 
{
    if (node == NULL) 
    {
      return;
    }

    total_sum = total_sum + node->data;
    no_of_nodes = no_of_nodes + 1;

    get_average(node->left);
    get_average(node->right);
}


int main()  
{  
    Node* root = nullptr;
    /* Binary tree:
              16
            /   \
           /     \
          10      25
         /  \    /  \
        /    \  /    \
       7    15 18     30

    */

    root = new Node(16);
    root->left = new Node(10);
    root->right = new Node(25);
    root->left->left = new Node(7);
    root->left->right = new Node(15);
    root->right->left = new Node(18);
    root->right->right = new Node(30);

    get_average(root);

    cout<<"The average is "<<(total_sum/no_of_nodes)<<endl;

    return 0;  
}  

Output:

The average is 17