J8VbNz - Online C Compiler & Debugging Tool

#include <stdio.h>
#include <stdlib.h>

// Define the structure of a tree node
struct Node {
    int data;
    struct Node* left;
    struct Node* right;
};

// Function to create a new node
struct Node* createNode(int data) {
    struct Node* newNode = (struct Node*)malloc(sizeof(struct Node));
    newNode->data = data;
    newNode->left = NULL;
    newNode->right = NULL;
    return newNode;
}

// Function to calculate the size of the tree
int calculateSize(struct Node* root) {
    if (root == NULL)
        return 0; // Base case: an empty tree has size 0
    return calculateSize(root->left) + calculateSize(root->right) + 1;
}

int main() {
    // Creating the tree shown in your image
    struct Node* root = createNode(5);
    root->left = createNode(1);
    root->right = createNode(6);
    root->left->left = createNode(3);
    root->right->left = createNode(7);
    root->right->right = createNode(4);

    // Calculate the size of the tree
    int size = calculateSize(root);

    // Output the size
    printf("The size of the tree is: %d\n", size);

    return 0;
}