Java trees and graphs

Console-based creation of graphs or trees using Java

In order to determine the width of a tree, it is necessary to use the formula: width = gap * stemwidth + gap. To calculate the gap, one can refer to the second answer provided in the response to the question «How to print binary tree diagram?» (since this answer is applicable to all types of trees, not just binary ones).

Java drawing graphs or trees in console

Printing ASCII trees can be done with minimal code by referring to the second response in the question about how to create a diagram using print binary tree.

This answer is not exclusively for binary trees, unlike the previous one.

If you’re searching for a tree drawing library in Java, I suggest using text-tree. This library can draw trees in various styles and offers extensive configuration options.

some text ├─── more text ├─── and more │ ├─── still more │ ╰─── more ╰─── the end 

To be completely transparent, I must mention that I am the creator of text-tree.

To the best of my recollection, it is possible to create ASCII charts using javaplot.

Java drawing graphs or trees in console, The output should be able to display trees, binary trees ( linked by @lbalazscs here ), but also simple graphs such as bargraphs or so. I will let this question «unanswered» for a while, and if there is no probant answer, @lbalazscs will get the point 😉 java graphics charts console command-line-interface. Share. Code samplesome text+— more text+— and more¦ +— still more¦ ?— moreFeedback

How To Create A Christmas Tree In Java In 5 Minutes

How To Create A Christmas Tree In Java In 5 Minutes Just giving you a quick and easy way of creating a Christmas tree in Java ! Computer: Macbook Pro Mi

Java graph library for drawing Probability Tree Diagrams

Consider using jgraph or generating a graphviz file and rendering it independently. Alternatively, you can utilize a Java graphviz API.

Drawing graphs on java, JGraphT and JGraph are another option. JGraph is used for rendering graphs in the GUI and handling user interaction while JGraphT is the underlying graph model, data structures and algorithms. Share. edited Dec 7, 2013 at 12:53. Frodo Baggins. 8,065 6 43 55. answered Jun 5, 2010 at 20:39.

Drawing a tree-like graph — how to organize the storage array?

Is it necessary to employ an array? Instead of using an array, a ‘Node’ class with child Node references can be implemented for solving this issue. This approach facilitates a recursive algorithm that can be used to locate a specific Node. To begin with, all you require is a reference to the root Node.

public class Node < private Node parent; private Listchildren; public Node findNode(String nodeName) < // Is it this node? // Iterate through all child nodes, calling findNode on each >> 

How to draw graphs using Java Swing, Sorted by: 1. When I run this code, no graph gets drawn. You should NOT be overriding paint () on a JFrame. Custom painting is done by overriding paintComponent () of a JPanel and then you add the panel to the frame. Read the section from the Swing tutorial on Custom Painting for more information and …

Drawing christmas trees using nested for loops

The spaces on either side of the stem are equal to one-third of the overall width, given that the stem occupies one-third of the total width. To calculate this, use the formula (width — stemWidth)/2, which yields a result of one-third of the width in this particular case.

I substituted the modula with «(height -1) / 5 +1» which rounds up to the next integer. This formula returns 1 (equivalent to 2 rows including 0) for heights 1, 2, 3, 4, or 5 and 2 (equivalent to 3 rows including 0) for heights 6, 7, 8, 9, or 10. I believe this is the desired outcome you were aiming for with the modula, but I cannot be certain.

import java.util.Scanner; public class TreeStructures < static Scanner scnr = new Scanner(System.in); static int height; public static void main(String[] args) < System.out.print("How tall should the top of the tree be? "); height = scnr.nextInt(); System.out.println(); if (height >= 5 && height else < System.out.println("That's not a valid size. I can only do trees from 5 to 20"); System.out.println("Quitting now."); >> public static void flatTree() < int width = (height * 2) - 1; // first for loop to print number of rows for (int i = 1; i // println to print rows in. System.out.println(); > //first for loop to print out rows for the bottom part of tree for (int i = 0; i > else < //second for loop to print out width for the bottom part of the tree for (int j = 0; j > System.out.println(); > > public static void xmasTree() < int width = height * 2 - 1; // NESTED LOOPS // first for loop to print amount of rows for (int i = 0; i < height; i++) < // second for loop for print out spaces to match the tree level for (int j = 0; j < height - i; j++) < System.out.print(" "); >// third for loop to print out stars for (int k = 0; k < (2 * i + 1); k++) < System.out.print("*"); >System.out.println(); > // first for loop to determine amount of rows for bottom for (int i = 0; i for (int j = 0; j System.out.println(); > > > 

How tall should the top of the tree be? 10 Flat tree: ******************* ******************* ******************* ******************* ******************* ******************* ******************* ******************* ******************* ******************* ******** ******** ******** Xmas tree: * *** ***** ******* ********* *********** ************* *************** ***************** ******************* ******* ******* ******* 

To achieve perfect centering, it’s necessary to manipulate the stem width slightly and use a little trickery.

In order to achieve this, it is important to understand the desired structure of the tree.

witdh = gap * stemwidth + gap

Based on that, it is simple to infer that there is a disparity.

The width can be determined by re-inserting it again.

The formula for calculating the width involves adding the stem width to half of the difference between the total width and the stem width, and then adding another half of the difference between the total width and the stem width.

The value of stemwidth can be calculated by subtracting twice the difference between width and stemwidth divided by two from width.

One could demonstrate the accuracy of this equation by examining and assessing the right side.

In the realm of discrete mathematics, it is necessary to consider both rounding and the leftover values that result from division.

During gap calculation, division rounding occurs and results in the loss of any remaining remainder.

By utilizing the aforementioned equation, we determine a revised stemwidth that incorporates the lost remainder in a discrete manner, resulting in a slightly larger but centered stemwidth.

public static void xmasTree() < int width = height * 2 - 1; int stem = width - 2*width/3; // NESTED LOOPS // first for loop to print amount of rows for (int i = 0; i < height; i++) < // second for loop for print out spaces to match the tree level for (int j = 0; j < height - i; j++) < System.out.print(" "); >// third for loop to print out stars for (int k = 0; k < (2 * i + 1); k++) < System.out.print("*"); >System.out.println(); > // first for loop to determine amount of rows for bottom for (int i = 0; i //here we put the formula to use, instead of using width/3, the equivalent is used, that takes rounding into account. for (int j = 0; j < width - 2*(width/3); j++) < System.out.print("*"); >System.out.println(); > 

Java graph library for drawing Probability Tree Diagrams, 1 Answer. Sorted by: 2. Try jgraph or just create a graphviz file and render it separately or use a Java graphviz API. Share. answered May 14, 2012 at 14:40. Dave Newton. 157k 24 250 301. Add a comment.

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Graph Data Structure in Java

Graph traversal and searching with Depth-First and Breadth-First Search

Depth-First Search (DFS) and Breadth-First Search (BFS) are algorithms for traversing or searching a graph

• DFS starts at an arbitrary node and explores as far as possible along each branch before backtracking BFS starts at an arbitrary node and explores all of the neighbor nodes at the current level before moving on to the next level Thus DFS is better when the target is far from the source while BFS is better when the target is close to the source
• DFS uses a Stack while BFS uses a Queue data structure to backtrack vertices on the traversal path
• DFS consumes less memory than BFS as BFS has to store all the children at each level

Detect Cycle in a Directed Graph

You can use DFS to detect a cycle in a directed graph. When visiting a vertex v and its adjacency vertices, if there is a back edge (w, v) which directs to v then that graph has a cycle

Topological Sort with Directed Acyclic Graph

Topological sort is an algorithm which takes a directed acyclic graph and returns a list of vertices in the linear ordering where each vertex has to precede all vertices it directs to

DFS and the above vertex degree theory can be used to implement the topological sort

Find shortest paths between vertices

The shortest path is a path between two vertices in a graph such that the total sum of the weights of the constituent edges is minimum

You can implement an algorithm to find the shortest path by using Breadth-First Search (BFS), Dijkstra, Bellman-Ford, and Floyd-Warshall algorithms

Giau Ngo

Giau Ngo is a software engineer, creator of HelloKoding. He loves coding, blogging, and traveling. You may find him on GitHub and LinkedIn

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Traversing binary tree and graphs in Java

In order traversal. Print all nodes in order from a binary tree. left, current, and then right.

public void inOrder(Node node) < if (node != null) < inOrder(node.left); System.out.println(node.data); inOrder(node.right); >>

Pre order traversal. Print current node first before its child nodes. current, left, and then right.

public void preOrder(Node node) < if (node != null) < System.out.println(node.data); preOrder(node.left); preOrder(node.right); >>

Post order traversal. Print child nodes first and then current node, left, right, and then current.

public void postOrder(Node node) < if (node != null) < postOrder(node.left); postOrder(node.right); System.out.println(node.data); >>

Class definitions for a graph. The Graph class is needed because a graph can have more than one root nodes and each of them can be isolated from others. Thus, sometimes you can’t visit all the nodes from a single root node.

public class Graph < public Node[] nodes; >public class Node < int data; boolean isVisited; Node [] nodes; public Node(int data) < this.data = data; >>

Search a graph using DFS, Depth First Search.

public void dfsSearch(Node root) < if (root == null) return; System.out.println(root.data); root.visited = true; for (Node node : root.nodes) < if (!node.isVisited) < dfsSearch(node); >> >

Search a graph using BFS, Breadth First Search.

public void bfsSearch(Node root) < QueuenodeQueue = new Queue<>(); root.isVisited = true; nodeQueue.enqueue(root); while (!nodeQueue.isEmpty()) < Node node = nodeQueue.dequeue(); System.out.println(node.data); for (Node n : node.nodes) < if (!n.isVisited) < n.isVisited = true; nodeQueue.enqueue(n); >> > >

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