Why Trees Exist and What Linked Lists and Arrays Cannot Do in DSA C++ - See It Work

Why Trees Exist and What Linked Lists and Arrays Cannot Do

📖 Scenario: Imagine you are organizing a family reunion. You want to keep track of family members and their relationships. Using just a list or an array makes it hard to show who is whose parent or child. Trees help us organize such hierarchical data clearly.

🎯 Goal: Build a simple tree structure in C++ to represent family relationships and see why linked lists and arrays cannot easily show these connections.

📋 What You'll Learn

Create a simple tree node structure with a name and pointers to children

Add a root node representing the grandparent

Add two children nodes representing the children of the grandparent

Print the family tree showing the grandparent and their children

💡 Why This Matters

🌍 Real World

Trees are used to represent hierarchical data like family trees, file systems, and organizational charts.

💼 Career

Understanding trees helps in software development tasks like building menus, databases, and search algorithms.

1

Create the Tree Node Structure

Write a struct called TreeNode with a string member called name and two TreeNode* members called left and right. Initialize left and right to nullptr.

DSA C++

// Your code here

Hint

Think of TreeNode as a box holding a name and two pointers to other boxes (children).

2

Create the Root Node

Create a TreeNode variable called grandparent and set its name to "Grandparent".

DSA C++

#include 
#include 
using namespace std;

struct TreeNode {
    string name;
    TreeNode* left = nullptr;
    TreeNode* right = nullptr;
};

// Your code here

Hint

Think of grandparent as the top box in your family tree.

3

Add Children to the Root Node

Create two TreeNode variables called parent1 and parent2. Set their name to "Parent1" and "Parent2" respectively. Then set grandparent.left to point to &parent1 and grandparent.right to point to &parent2.

DSA C++

#include 
#include 
using namespace std;

struct TreeNode {
    string name;
    TreeNode* left = nullptr;
    TreeNode* right = nullptr;
};

int main() {
    TreeNode grandparent;
    grandparent.name = "Grandparent";

    // Create two children nodes and link them to grandparent
    // Your code here

    return 0;
}

Hint

Each child is a box connected to the grandparent box by pointers.

4

Print the Family Tree

Print the grandparent.name, then print grandparent.left->name and grandparent.right->name on separate lines.

DSA C++

#include 
#include 
using namespace std;

struct TreeNode {
    string name;
    TreeNode* left = nullptr;
    TreeNode* right = nullptr;
};

int main() {
    TreeNode grandparent;
    grandparent.name = "Grandparent";

    TreeNode parent1;
    parent1.name = "Parent1";
    TreeNode parent2;
    parent2.name = "Parent2";

    grandparent.left = &parent1;
    grandparent.right = &parent2;

    // Print the family tree names
    // Your code here

    return 0;
}

Hint

Use cout and the arrow operator -> to access child names.