Welcome to the Tree Problems section of the Coding Problems lesson. In this section, we will explore various problems related to trees.

As a senior engineer with intermediate knowledge of Java and Python, you are well-equipped to dive into tree-related problems. Trees are hierarchical data structures that consist of nodes connected by edges. They are commonly used to represent hierarchical relationships, such as family trees or organization charts.

By understanding different algorithms and techniques for working with trees, you can improve your problem-solving skills and be better prepared for coding interviews.

Let's start by examining a common problem related to trees: finding the maximum depth of a binary tree.

Here's some Java code that demonstrates how to find the maximum depth of a binary tree:

1class TreeNode {
2    int val;
3    TreeNode left;
4    TreeNode right;
5
6    TreeNode(int val) {
7        this.val = val;
8    }
9}
10
11public class Main {
12    public static int maxDepth(TreeNode root) {
13        if (root == null) {
14            return 0;
15        }
16        int leftDepth = maxDepth(root.left);
17        int rightDepth = maxDepth(root.right);
18        return Math.max(leftDepth, rightDepth) + 1;
19    }
20
21    public static void main(String[] args) {
22        // create a binary tree
23        TreeNode root = new TreeNode(3);
24        root.left = new TreeNode(9);
25        root.right = new TreeNode(20);
26        root.right.left = new TreeNode(15);
27        root.right.right = new TreeNode(7);
28
29        int depth = maxDepth(root);
30        System.out.println("Maximum Depth: " + depth);
31    }
32}

In this code, we define a TreeNode class that represents a node in a binary tree. The maxDepth function recursively calculates the maximum depth of the given binary tree by calculating the maximum depth of its left and right subtrees and adding 1 to the maximum of those two depths.

You can modify this code to solve different tree-related problems or explore other tree algorithms and techniques.

Happy coding!