What would be a good and simple algorithm to find the shortest route between two points in a 2D array[grid] ? There can be certain obstacles in the grid i.e. some of the cells may be inaccessible. I tried googling for it and found that A* is the best for this but I am just a beginner and would like to start with something much simpler.
View RepliesI am using the shortest path algorithm to determine the connection between individuals within a given array. The array is written into the code and not read from external files.
When I am having problem is .. i am having problems how to prompt the user for the starting point or vertex and read that prompt to determine the starting point in the array. I know that this code :
computePaths(v0);
determines the starting point. i want to read "v0" from the user prompt.
total code being used
import java.util.PriorityQueue;
import java.util.List;
import java.util.ArrayList;
import java.util.Collections;
import java.io.IOException;
import java.util.Scanner;
class Vertex implements Comparable<Vertex>
[Code] .....
This is what he wants: He wants us to prompt the user to input x values and y values (that will be entered into an array when clicking one of the two buttons (this one will say: Add point)). When they click the second button (draw lines), it should take all the points and draw a line that connects all the points together using a method that we write. In the method we have to call the paint method up which the lines will be drawn. The lines drawn should be touching every point added. It shouldn't have parameters. It will also use Graphics painter = getGraphics(); We can't use frames either.
I have everything up until the method understood.
How to write a method that will draw a line from points inputted that is called up in the action listener when the second button (draw lines) is pressed.
I have been looking around and I cannot seem to find which algorithm java uses for its sort method. Merge, sort etc.
While I am on the topic BinaryTree is a balanced heap right?
Are there any libraries for depth or breath first search?
Is the ArrayList a double linked list?
In one part of my small code, I want to make a sky which will have area of 200 * 200 pixels, and inside I want to have 100 randomly placed stars (I tried to make an array of 100 elements - of class "Point").Each star should have its x and y coordinate, and I don't know how to do it. I tried many things.
import java.util.Random;
import java.awt.Point;
public class Sky {
private Point[] stars = new Point[100];
public Sky() {
for(int i = 0; i< stars.length; i++){
Random r = new Random();
int u = r.nextInt(199);
int v = r.nextInt(199);
//x[0].setLocation(u,v);
21stars[0].x = 5;
[code]...
I need to write a program but I am having hard time filling an array of triangles...we are suppose to have 3 different classes..1 class of points..1 class of triangles and 1 main method which apply all those..here what I have been come up so far for the point class which I believe is good..
public class Point {
private float x;
private float y;
//Making x equal to the x coordinate and y equal to the y coordinate like on a graph
public Point(float xCoordinate, float yCoordinate) {
x = xCoordinate;
y = yCoordinate;
[Code] ....
Now here is my question how I am suppose in the main method fill an array of triangles for 100 triangles or less?
I am trying to add Point objects into an Array.This is my code to read in data
Java Code:
public void readRoadMap(File road) {
try{
String line;
BufferedReader br = new BufferedReader(new FileReader(road));
while((line = br.readLine()) !=null){
this.points.add(new Point(line));
[code]....
I was given some code by a professor to add some features to as part of an assignment. However, the code itself doesn't seem to work.
import java.util.HashSet;
import java.util.InputMismatchException;
import java.util.PriorityQueue;
import java.util.Scanner;
import java.util.Set;
public class DijkstraPriorityQueue
[Code] ....
The method to find minimum distance is nonfunctional...I receive an error that the types are incompatible. I can't do the assignment if the base code doesn't work to begin with...
i am to add jpanels to an arraylist such that it forms a grid like a 2d array. when i add the first colunm and have to iterate and store the next sequence of jpanels it still stores it in get(0), instead of get(1).
[/ temp.add(jPanel9);
temp.add(jPanel10);
temp.add(jPanel11);
temp.add(jPanel12);
temp.add(jPanel13);
temp.add(jPanel14);
temp.add(jPanel15);
[Code]...
I am attempting to make a 5x5 bingo board. My array generates 75 numbers(15 per bingo letter) and displays them in a random order. What I am having trouble figuring out is how to fill the 5x5 grid with 25 numbers from my array. And yes, my code is probably much longer and much more redundant than it needs to be. Also, I think I'm using cells and grids terribly wrong (possibly the entire java language) but I'm not sure.
import java.util.*;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JLabel;
import java.awt.event.*;
import java.util.ArrayList;
import java.awt.GridLayout;
import javax.swing.JButton;
public class bingoboard extends JFrame
[code]...
Operator is undefined for argument type. Error is located at the end of the binary search method array[position] < key
import java.util.Arrays;
public class binarySearch {
public static <T extends Comparable<T>> int binarysearch(T key, T[] array) {
int start = 0;
int end = array.length - 1;
int position =-1;
while (start <= end && position == -1) {
[Code]....
I'm using JavaKara (a graphic Java software to learn coding) on my classes at the moment and we're asked to transform something like this:
In the inverse, where you can see clovers there must not be any and where there aren't you must plant them. PLUS YOU MUST SWITCH THE FIGURE HORIZONTALLY.
This is the result i should obtain:
public class InvertiECapovolgi extends JavaKaraProgram {
public void myProgram() {
boolean arrayquadrifogli[][] = new boolean[world.getSizeY()][world.getSizeX()]; //[rows][clumns]-->[Y axis][X axis] in kara
for (int y = 0; y < arrayquadrifogli.length; y++){ // My Ladybug starts to run through the whole grid
[Code] ....
How to switch everything horizontally!
This is my result:
My ultimate question is, how do i have to edit the second loop, and why, to obtain the horizontally reversed result i'm supposed to obtain?
My issue is that when I run my search, it does find a goal. However, when I try and print the route using my print route method, it just gets stuck in a loop of printing the same two nodes. What is wrong with My A* implementation?
package search;
import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedList;
[code]....
i need to sort these runners into time order shortest first, the classes both work i just cant get the method sortRunnerList() to work
Java Code:
public class Runner implements Comparable <Runner>
{
/* static variables */
private static int nextNumber;
// To be added by students in Question 3, part (i)(a) and part(iv)(a)
/* instance variables */
private int number; // runner's number
private String name; // runner's name
[Code] .....
How would I go about inputting the negative values in the array in case 1 the array comes from the user, case 2 from the text file? The sum prints perfectly fine with positive values but if I input negative values it just completely ignores them.
case 1:
int sum;
System.out.print("Enter list of comma-delimeted integers: ");
Scanner scan = new Scanner(System.in);
String input2=scan.next();
String[] num = input2.split(",");
int[] a= new int[num.length];
[Code] ....
I am working with an Adjacency Matrix to try to find the MST of a graph. Along the way I have hit a snag that I am not sure how to get around. When running the program I will parse through each row of the matrix and find the smallest weight. However when trying to reset the row at the end of the lowest sort I cannot move to the next row.
The graph looks like this:
My Matrix was created from the graph and I have determined by starting at Vertex W my path should looks like this:
W->R->D->H->G->S->C->B->A
I'm trying write a Dijkstra's implementation in java. First off, here is the algorithm:
package lab3;
import java.util.HashMap;
import java.util.Stack;
/**
* Compute shortest paths in a graph.
*
* Your constructor should compute the actual shortest paths and maintain all the information needed to reconstruct them. The returnPath() function should use this information to return the appropriate path of edge ID's from the start to the given end.
*
* Note that the start and end ID's should be mapped to vertices using the graph's get() function.
*/
class ShortestPaths {
Multigraph graph;
final int INF = Integer.MAX_VALUE;
PriorityQueue<Integer> Q;
[Code] ....
I followed someone else psuedocode very closely but for whatever reason, my edge[] array is just full of null data, which means I can't actually return the shortest path. Why that's happening/how to fix it? Maybe I'm not understanding dijstra's correctly.
how to get shortest path between two nodes in adjacency matrix using with undirected weighted graph using BFS algoritham java program??
View Replies View RelatedI am taking the Class Algorithms and Datastructures and got an assignment for Lab that really throws me off. The goal is to create an Array out of a given CSV file, implement several Methods that get the size of array, etc.
I am still stuck in the first part where the CSV has to be imported into the Array. My problem is that I need a mechanism that figures out the needed size for the Array, creates the array, and only then transfers the data from the CSV.
The list consists of the following wifi related values:
MAC-Adress, SSID, Timestamp, Signalstrength.
These are on the list, separated by comma. The Columns are each of these, and the rows are the four types of values making up the information on a certain wifi network.
The catch is, we are not allowed to use any of the following:
java.util.ArrayList
java.util.Arrays
and any class out of java.util.Collection.
So far I used the BufferedReader to read in the file and tried to implement the array, but I get an arrayindexoutofboundsexception.
Below is my Code (Its still an active construction zone):
public class WhatsThere {
public WhatsThere(String wifiscan) throws IOException {
}
public static void main(String[] args) throws IOException {
// WhatsThere Liste = new WhatsThere(String wifiscan);
String[][] arrayListe = new String[0][0];
[Code] ....
So as part of my program I have to find the corners of an array (the array can vary in size but is always square) but I'm not exactly sure how to do this. I thought of one possible way but I am not sure if I can do it or how to write it,
if array[row][col] = [0][0] or [row length][col length] or [0][col length] or [row length][col length].
I'm just giving examples of what I am trying to find here I know none of these are actual syntax. I don't even know if I can check whether an array's coordinates are equal to coordinates on that array or not. How I can write this or if there is another way to do it? If yes, what about edges of the array?
I have a given array of numbers, and I have to find the longest decreasing sub-array, but the thing is that the elements don't have to be next to each other!
For example, the longest decreasing sub-array for this array : 546 -156 165 -156 -56 -13 5
is 3 (check the bold numbers)
Until now, I have nearly finished my code, but I have one problem...
private static int decreasing(int[] a) {
int result=1, temp=0, br=1;
//Checking all the elements one by one:
for(int i=0;i<a.length;i++){
temp=a[i]; //placing the element on a temp value
[Code] ....
The problem with this code is that it's not smart.. let's say I have : 100 -500 90 80 70
Once it hits -500, none of the other if's with pass....
what I needed to know to complete the lesson, but now it just tells me what the output should be and I have to research the information on my own. anyways, here is my code from the previous lesson:
import java.util.Random;
import java.util.Scanner;
public class tnArray {
public static void main(String[] args) {
int [] array;
[code]....
Now I have to change it so that instead of counting the number of times a number will appear in the array, I must output which slot in the array the number is in.
I am trying to display Largest value and Smallest value in an array but when I execute I get Largest value as 0.
Following is the code:
package simpleArray;
import javax.swing.JOptionPane;
class ArrayInteractive {
static String ch = "Q";
static boolean flag = true;
static String a[];
[code]....
So what I'm trying to do is write a code in java which finds a path through a maze. I want it to go through the maze and determine if there's a * symbol at that location or not. If there is a * symbol at the specified location then the program would search for another position until it finds one without the * symbol and if it can't then I'll have the program return null. I also want it to implement backtracking which I'm not sure how to do. Here's my code so far
private boolean findPath(int fromRow, int fromCol, int toRow, int toCol){
boolean solved = true;
for(int i=fromRow; i<toRow; i++){
for(int j=fromCol; j<toCol; j++){
if (x[i][j] == ('*')){
//do something
}
}
}
return false;
}
the code isn't finished yet however what I'm not sure is what do I do with the if statement and how do I implement backtracking?
An array which contain a list of names. I let for a user input and I use that to search through the array. For example lets say the string name "Christian" is stored inside the names array and the user types in Chri, the program looks in the array and finds a name that contains Chri and prints them out. How do I go about doing this?
View Replies View RelatedHow can I find the overall averages of the columns in this array?when i run my code it gives me an output that looks like this (showing me wrong averages): 0 1 2 3 overall grade
Badger,Bradley 37 70 51 48 68.66666666666667
Emu,Emma 35 81 75 40 72.83333333333334
Aardvark,Alice 42 85 22 0 65.11111111111111
Dodo,Donald exc 12 25 0 54.17391304347826
Cassowary,Cassie 50 97 72 68 62.758620689655174
my code is :
Java Code: public static double[] computeAllGrades(int[][] scoreTable, int[] itemPointValues)
{
{
double totalPoints = 0;
double totalPointsPossible = 0;
double allGrades[];
double grade =0;
[code]....