Java: Find the maximum depth of a given a binary tree

Last update on May 12 2025 13:12:28 (UTC/GMT +8 hours)

Max Depth of Binary Tree

Write a Java program to find the maximum depth of a given binary tree.
Sample Output: The Maximum depth of the binary tree is: 3

Sample Solution:

Java Code:

class Node {
    int data;
    Node left, right;

    public Node(int item) {
        // Constructor to initialize a node with given data
        data = item;
        left = right = null;
    }
}

public class BinaryTree {
    Node root;

    public int maxDepth(Node root) {
        // Recursive function to calculate the maximum depth of the binary tree
        if (root == null)
            return 0;
        int left_Depth = maxDepth(root.left);
        int right_Depth = maxDepth(root.right);
        int bigger = Math.max(left_Depth, right_Depth);
        return bigger + 1;
    }

    public static void main(String args[]) {
        BinaryTree tree = new BinaryTree();
        tree.root = new Node(55);
        tree.root.left = new Node(21);
        tree.root.right = new Node(80);
        tree.root.left.left = new Node(9);
        tree.root.left.right = new Node(29);
        tree.root.right.left = new Node(76);
        tree.root.right.right = new Node(91);

        // Create a binary tree and calculate its maximum depth
        System.out.println("The Maximum depth of the binary tree is: " + tree.maxDepth(tree.root));
    }
}

Sample Output:

The Maximum depth of the binary tree is: 3  

Flowchart:

For more Practice: Solve these Related Problems:

• Modify the program to find the minimum depth of a binary tree.
• Write a program to find the depth of a specific node.
• Modify the program to count the number of leaf nodes.
• Write a program to find the depth using an iterative approach.

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