1. Implement the basic Depth First Search (DFS) for a graph.

2. Write a function to perform DFS on a tree.

3. Implement a function to find the number of connected components in an undirected graph using DFS.

4. Write a function to detect a cycle in an undirected graph using DFS.

5. Implement a function to find the path from the root to a given node in a tree using DFS.

6. Write a function to find all leaf nodes in a binary tree using DFS.

7. Implement a function to find the depth of a binary tree using DFS.

8. Write a function to print all nodes at a given depth in a binary tree using DFS.

9. Implement a function to perform in-order traversal of a binary tree using DFS.

10. Write a function to perform pre-order traversal of a binary tree using DFS.

11. Implement a function to perform post-order traversal of a binary tree using DFS.

12. Write a function to find the sum of all nodes in a binary tree using DFS.

13. Implement a function to find the maximum value in a binary tree using DFS.

14. Write a function to find the minimum value in a binary tree using DFS.

15. Implement a function to count the number of nodes in a binary tree using DFS.

16. Write a function to find the height of a binary tree using DFS.

17. Implement a function to check if two binary trees are identical using DFS.

18. Write a function to find the diameter of a binary tree using DFS.

19. Implement a function to find the lowest common ancestor (LCA) of two nodes in a binary tree using DFS.

20. Write a function to find the longest path in a binary tree using DFS.

21. Implement a function to find all paths from the root to leaf nodes in a binary tree using DFS.

22. Write a function to find the sum of all left leaves in a binary tree using DFS.

23. Implement a function to find the sum of all right leaves in a binary tree using DFS.

24. Write a function to convert a binary tree to a doubly linked list using DFS.

25. Implement a function to clone a binary tree using DFS.

26. Write a function to check if a binary tree is balanced using DFS.

27. Implement a function to find all ancestors of a given node in a binary tree using DFS.

28. Write a function to find all descendants of a given node in a binary tree using DFS.

29. Implement a function to perform DFS on a graph represented as an adjacency matrix.

30. Write a function to perform DFS on a graph represented as an adjacency list.