---
id: tree
title: Tree
---

- Find the height of a tree.
- Find the longest path from the root to leaf in a tree.
- Find the deepest left leaf of a tree.
- Print all paths of a binary tree.
  - [Source](http://blog.gainlo.co/index.php/2016/04/15/print-all-paths-of-a-binary-tree/)
- Second largest element of a BST.
  - [Source](http://blog.gainlo.co/index.php/2016/06/03/second-largest-element-of-a-binary-search-tree/)
- Given a binary tree and two nodes, how to find the common ancestor of the two nodes?
  - [Source](http://blog.gainlo.co/index.php/2016/07/06/lowest-common-ancestor/)
- Find the lowest common ancestor of two nodes in a binary search tree.
- Print the nodes in an n-ary tree level by level, one printed line per level.
- Given a directory of files and folders (and relevant functions), how would you parse through it to find equivalent files?
- Write a basic file system and implement the commands ls, pwd, mkdir, create, rm, cd, cat, mv.
- Compute the intersection of two binary search trees.
- Given a binary tree, output all the node to leaf paths of it.
- Given a string of characters without spaces, is there a way to break the string into valid words without leftover characters?
- Print a binary tree level by level.
- Determine if a binary tree is "complete" (i.e, if all leaf nodes were either at the maximum depth or max depth-1, and were 'pressed' along the left side of the tree).
- Find the longest path in a binary tree. The path may start and end at any node.
- Determine if a binary tree is a BST.
- Given a binary tree, serialize it into a string. Then deserialize it.
- Print a binary tree by column.
- Given a node, find the next element in a BST.
- Find the shortest subtree that consist of all the deepest nodes. The tree is not binary.
- Print out the sum of each row in a binary tree.
- Pretty print a JSON object.
- Convert a binary tree to a doubly circular linked list.
- Find the second largest number in a binary tree.
- Given a tree, find the longest branch.
- Convert a tree to a linked list.
- Given two trees, write code to find out if tree A is a subtree of tree B.
- Deepest node in a tree.
  - [Source](http://blog.gainlo.co/index.php/2016/04/26/deepest-node-in-a-tree/)