Find the maximum depth of a binary tree

public class TreeNode { int val; TreeNode left; TreeNode right; TreeNode(int x) { val = x; } } public class Solution { public int maxDepth(TreeNode root) { TreeNode focusNode = root; TreeNode focusNode2 = root; int count = 0; int count1 = 0; boolean

Calculating descendants in a tree

I've created a structure to represent a simple tree like this: A / \ B C / \ / \ D E F G Each node is a Record which is my custom class with some fields inside. In the following example is simplified with just the field that contains the node's child

Counting with recursion in binary trees confuse me

I am trying to learn as much as i can about tree's and their algorithm's. And it seems like i can't really learn how recursion works when i want to count something in binary tree. For example if i want to count nodes or leaves or something else. When

Modeling an arbitrary tree in C ++ (with iterators)

I am looking for a way to model a tree with an arbitrary amount of childrens per nodes. This answer suggests using the Boost Graph Library for this task: What's a good and stable C++ tree implementation? The main operations that I need to perform are

How to learn to learn (Tree) on several attributes?

I am using python and scikit-learn's tree classifier in a little fictive machine learning problem. I have binary outcome variable (wc_measure) and I believe it is dependent on a few other variables (cash, crisis, and industry). I tried the following:

Give unique IDs to all nodes?

I am making a class in Python that relates a lot of nodes and edges together. I also have other operations that can take two separate objects and merge them into a single object of the same type, and so on. However, I need a way to give every node a

How to apply SQL LIMIT for three structure data?

I use a famous method for showing the three comment from SQL. How I can display only first three root comment with a all sub-comment? I tried to make something like: SELECT * FROM NAMES ORDER BY pid LIMIT 3 ASC, Id ASC LIMIT 3 But LIMIT is not suppor

Recursive deletion of tree elements in python

seen2 = set() def eliminate_abs(d): ##remove all entries that connect to the abstraction node, type(d) = list def rec(x): if x not in seen2: seen2.add(x) a = x.hypernyms() if len(a) != 0: kk = a[0] if'abstraction',str(kk)): syns.remove(ii)

How to make the child's tree of the parent categories?

I have a problem when i want to create tree structure in my data this is my data for sample $categories = array( array( 'id' => 2 , 'name' => 'banana', 'parent' => 1 ), array( 'id' => 1 , 'name' => 'fruit', 'parent' => 0 ), array( 'id' =

Loop in a binary tree represented as an adjacency list

I attained an interview where I was asked a question as below: You are given with parent -----> child relationships i.e. N1 ---> N2 where N1 is the parent of N2. This is nothing but representing a binary tree in adjacency list form. So I had to find

Automatic correction algorithm

I want to implement the following in C++: 1) Check whether the given word exists in a dictionary. The dictionary file is a huge file; consider 100MB or 3-4 Million words. 2) Suggest corrections for the incorrect word. 3) Autocomplete feature. My Appr

Drawing of trees without any constraint on the degrees

I'm working on visualization of my distributed algorithm which solves problems on trees. I have to draw a rooted tree which is given as an input. Currently, I know how to handle the case if every node has at most 2 children. In this situation, for ev

Insert in the red black tree

I am taking an algorithms course and in my course slides, there is an example of insertion into a red-black tree: My question is, why don't we let "2" be a leaf node here? It looks like if we let it be a leaf node, then no condition of a red bla

Search an item in D3 - force or tree layout

Is there an example of searching for an element in a d3js layout (force directed or tree) and highlighting that element? I am thinking that there would be a text field where user enters values to search.I wrote a tool that allows browsing biological

Find all paths through a tree (nested dicts) from top to bottom

EDIT: See below for a suggested answer and how it's not quite right yet. There are many similar questions to this one on Stack Overflow, but none exactly like it in Python. I'm a programming novice, so please go easy. I have a tree of nested dictiona

Make a BST prolog from a list and return it in the parameter

I need to make a prolog predicate from_list/2 so that if i call from_list([], T) I will get back a tree containg the items in the list(ints) so far I have: from_list([], empty). from_list([X], T) :- insert(X, empty, T). from_list([X|Y], T) :- from_li

Insert in the binary tree without input sort

how can you build binary tree without sorting it, I.E if i have a input 5 4 9 8 1 2 7 how can you insert that into a reference based binary tree. I know this can be easily implemented with Array, but is it possible with reference base? Tree buildTree

Cross a tree dump (graph) similar to a diagram using C

I have a Scheme-like tree graph structure. I want to parse it using C into some in-memory representation and walk over it. It there any library or front-end of parser to do this? EDIT: I have parsed the following expression true && (false || true)

Code Synthesis - C ++ / Tree Subnode Serialization

I'm using this great tool ( to convert xsd into c++ code. I'm trying to obtain the xml string from a sub node, but the only thing that i can get is the all xml, like this: the all xml: <?xml version

Which tree should I use for indexing?

I'm thinking of experimenting with using a tree-structure for indexing as I want to test whether it is faster than my current indexing implementation which is in essence a hash based lookup. I've read up on various questions and articles about perfor

Crossing the SQL tree

I am not totally sure I am naming this right, but please bear with me. I am wondering if is possible to do something like this in SQL(MySQL specifically): Let's say we have tree-like data that is persisted in the database in the following table: mysq

Transform the map with multiple values ​​to the tree?

Given a randomly distributed set of keys, with each key mapped to a set of values, how would you transform it into multiple trees? Example Data Set NB2 => {NC2 ND2} ND1 => {NG1 NH1} NA1 => {NB1} NB1 => {NC1 ND1 NE1} NA2 => {NB2} NC1 => {