Level Order Traversal or Breadth First Search (BFS):

1. Binary tree traversal – Level Order Traversal  or Breadth First Search Algorithm (BFS) 
2. Find level in binary tree having maximum sum
3. Find sum of nodes in binary tree
4. Find height of binary tree
5. Find number of nodes or size of binary tree 
6. Count non-leaf nodes (left & right child) in binary tree
7. Count non leaf nodes in binary tree having one child node
8. Count non leaf nodes in binary tree
9. Find number of leaf nodes in a binary tree
10. Find maximum/ largest element in a binary tree
11. Check leaf nodes of binary tree are at same level
12. Find level of given node in binary tree
13. Find maximum width of binary tree
14. Spiral or Zigzag binary tree traversal
15. Print binary tree in reverse order

Depth First Search Algorithm:

1. Binary tree traversal algorithm (preOrder /postOrder/inOrder)
2. Find number of nodes or size of binary tree
3. Find diameter of binary tree
4. Find minimum & maximum element in binary tree
5. Find height of binary tree in java
6. Delete all nodes of a binary tree in java
7. Find root to leaf path sum equals given number binary tree
8. Find maximum sum in root to leaf path in binary tree
9. Print vertical order traversal of binary tree
10. Find vertical order sum in a binary tree
11. Connect nodes at same level (set next sibling) in a binary tree
12. LCA (Lowest common ancestor) in a binary tree
13. Print ancestors of node in a binary tree
14. Print paths from root to leaf nodes in binary tree
15. Print nodes at k distance from root in binary tree
16. Print nodes K distance from leaf nodes in a binary tree
17. Check two binary trees are equal or identical or same
18. Check given binary trees are Isomorphic
19. Check binary tree is Quasi-Isomorphic of other tree
20. Check given binary tree is mirror or symmetric tree
21. Convert binary tree to mirror/symmetric tree