Right Side View of Binary Tree in DSA C++ - Build from Scratch

Right Side View of Binary Tree

📖 Scenario: Imagine you have a tree of family members, and you want to see only the members visible from the right side. This means you want to see the rightmost member at each level of the tree.

🎯 Goal: Build a program that shows the right side view of a binary tree by printing the values of the nodes visible from the right side.

📋 What You'll Learn

Create a binary tree with the exact structure given

Use a variable to track the current level during traversal

Implement a function to find the right side view of the tree

Print the right side view nodes in order

💡 Why This Matters

🌍 Real World

Right side view of a binary tree helps in visualizing hierarchical data from a specific perspective, useful in UI trees, organizational charts, and decision trees.

💼 Career

Understanding tree traversal and views is important for software engineers working with data structures, algorithms, and system design.

1

Create the Binary Tree Structure

Create a binary tree with the exact structure below using the TreeNode struct. The root node has value 1, its left child is 2, right child is 3. Node 2 has a right child 5, and node 3 has a right child 4. Use pointers named exactly as root, node2, node3, node5, and node4.

DSA C++

#include 
using namespace std;

struct TreeNode {
    int val;
    TreeNode* left;
    TreeNode* right;
    TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
};

int main() {
    // Create the binary tree nodes and link them
    // Your code here
    return 0;
}

Hint

Start by creating nodes with new TreeNode(value). Then link them using ->left and ->right.

2

Add a Variable to Track Current Level

Add an integer variable called maxLevel and set it to 0. This will help track the deepest level visited during traversal.

DSA C++

#include 
using namespace std;

struct TreeNode {
    int val;
    TreeNode* left;
    TreeNode* right;
    TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
};

int main() {
    TreeNode* root = new TreeNode(1);
    TreeNode* node2 = new TreeNode(2);
    TreeNode* node3 = new TreeNode(3);
    TreeNode* node5 = new TreeNode(5);
    TreeNode* node4 = new TreeNode(4);

    root->left = node2;
    root->right = node3;
    node2->right = node5;
    node3->right = node4;

    // Add maxLevel variable here
    // Your code here
    return 0;
}

Hint

Declare int maxLevel = 0; before traversal starts.

3

Implement the Right Side View Function

Write a recursive function called rightView that takes TreeNode* node, int level, int& maxLevel, and prints the node's value if level is greater than maxLevel. Update maxLevel accordingly. Traverse the right child first, then the left child.

DSA C++

#include 
using namespace std;

struct TreeNode {
    int val;
    TreeNode* left;
    TreeNode* right;
    TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
};

void rightView(TreeNode* node, int level, int& maxLevel) {
    // Implement the recursive rightView function here
    // Your code here
}

int main() {
    TreeNode* root = new TreeNode(1);
    TreeNode* node2 = new TreeNode(2);
    TreeNode* node3 = new TreeNode(3);
    TreeNode* node5 = new TreeNode(5);
    TreeNode* node4 = new TreeNode(4);

    root->left = node2;
    root->right = node3;
    node2->right = node5;
    node3->right = node4;

    int maxLevel = 0;

    return 0;
}

Hint

Check if node is null first. Then if level > maxLevel, print the node value and update maxLevel. Recurse right child first, then left child.

4

Print the Right Side View

Call the rightView function from main with root, starting level as 1, and the maxLevel variable. Then print a newline.

DSA C++

#include 
using namespace std;

struct TreeNode {
    int val;
    TreeNode* left;
    TreeNode* right;
    TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
};

void rightView(TreeNode* node, int level, int& maxLevel) {
    if (node == nullptr) {
        return;
    }
    if (level > maxLevel) {
        cout val right, level + 1, maxLevel);
    rightView(node->left, level + 1, maxLevel);
}

int main() {
    TreeNode* root = new TreeNode(1);
    TreeNode* node2 = new TreeNode(2);
    TreeNode* node3 = new TreeNode(3);
    TreeNode* node5 = new TreeNode(5);
    TreeNode* node4 = new TreeNode(4);

    root->left = node2;
    root->right = node3;
    node2->right = node5;
    node3->right = node4;

    int maxLevel = 0;

    // Call rightView function and print newline
    // Your code here
    return 0;
}

Hint

Call rightView(root, 1, maxLevel); and then print a newline with cout << endl;.