Array Recursion Sum Is Not Producing Correct Output?
Feb 2, 2015
I am trying to sum up the elements of an array. When I test my code the sum is always off by one. For example if I input: 20, 40,30 it gives me 89 instead of 90.
This is what I have so far:
public static void main(String[args]){
int size = kbd.nextInt();
int [] myArray = new int [size]
//user inputs the elements of array
for(int i =0; i<myArray.length; i++){
myArray[i]= kbd.nextInt();
}
int total = sumNum(myArray,0, myArray.length-1)
System.out.println("The sum is"+ total);
}
How can I extract data from two different files but produce one output. For example, the first three columns are from text_file_1 and the last column (the last foruth column of the output) is from text_file_2...
I am writing a small program to convert temperature from Fahrenheit to Centigrade. I cannot figure out why I keep getting 0.00 for the Centigrade temperature output. Also, I cannot figure out how to get the F degree symbol before or after the temp. I know in JOptionPane the char = 176 is the code for it but im not sure how to code it into the program. My program keeps saying 0.00 for Centigrade temp on the output ....
import javax.swing.JOptionPane; import java.text.DecimalFormat; public class tempConversion { public static void main(String[] args) { String newDecimal;
[Code] .....
Okay I figured out the Degree symbol!(String DEGREE = "u00b0") phew... now only if i can get the correct output!
What it is supposed to do is decide whether a ceiling fan is on or off, and describe it (color, area, speed). This is all user input (even pi) so it should decide whether to turn it on or off but for some reason skips over my if/else if statements all together.
I've tried changing it around a bit, looking up what my problem may be but this problem remains the same. my code:
import java.util.Scanner; public class CeilingFan { final int slow = 1; final int medium = 2; final int fast = 3; private int speed; boolean on = false; private double radius = 5; private double pi = 3.1415; String color = "blue";
Why is my program not calculating the total and average of the price of the items and not printing it out?
Java Code: /* * To change this license header, choose License Headers in Project Properties. * To change this template file, choose Tools | Templates * and open the template in the editor. */ package assignment4;
[code]...
It prints out everything but the total of the items and I dont know why. :(
How to add the sum of an array with a recursion, but I don't understand how to use recursion. I just understand that it calls back the method. I am nearly done with the code.
import java.util.Scanner; class Question1{ public static void main(String[]args){ Scanner s = new Scanner(System.in); int size, sum; System.out.println("Please input how many numbers will be used"); size=s.nextInt();
i have to write a method, The method receives a parameter of two-dimensional array of integers. The method returns the number of the column which has the lowest sum of the integers.I'm allowed to use only recursion! no loops allowed!-of course i need to make a private method that will sum a column as a single array and then i have to do another private method that compares the column , but it doesn't really work .
so i have this question where it wants me to create a recursion method that takes ONLY THE ARRAY as a parameter, and without using loops or static variables inside the method, and then the method returns the smallest value in that array. However, i tried making the simple if statements where i compare the first element of the array with the second element using the length of the array and decreasing it to get the next elements and compare it again by calling the recursion method, but the problem is when i call the method again, the length does not decrease, even if i store it in a variable, the variable will initialize itself again, and the length wont change.
I am trying to sum up the elements of an array. When I test my code the sum is always off by one. For example if I input: 20, 40,30 it gives me 89 instead of 90.
This is what I have so far:
public static void main(String[args]){ int size = kbd.nextInt(); int [] myArray = new int [size] //user inputs the elements of array
public static int getSum(int[] data) { int sum = 0; for (int i = 0; i < data.length; i++) { sum += data[i]; } return sum;
[code]....
The input is the following arary (Its from the Junit test that fails this): [Integer.MIN_VALUE, -1, 0, 1, Integer.MAX_VALUE].I get an average of 0.0 when it should be -0.2.
Code isn't giving me the output that I want and keeps giving me NaN
What I want -
Enter the A value for the line: 2.45 Enter the B value for the line: 4 Enter the C value for the line: -8 Enter the x coordinate of the point: 2.17 Enter the y coordinate of the point: -4
Distance from the point to the line is: 3.9831092774319026
What I am getting
Distance from the point to the line is: NaN
Here is my code-
Tester-
import java.io.*; import java.util.*; class tester { public static double A; public static double B; public static double C; public static double distance; public static void main(String args[])
Am new to programming and am trying to create a system that is similar to a train timetable system.I want the user to be able to enter the stops between two stations ( from a preset list of 5 stations ) and this be saved as an array list, and this array list be saved accordingly within a 2D array so if they were to look in [1][2] there would be an arraylist of stops between station 1 and 2.I used this to initialise the array of arraylists (in a class i created called stops)
public void stops(){ for (int i = 0; i<5; i++){ for (int j=0; j<5; j++){ stopsArray[i][j]= new ArrayList<String>(); } } }
Then I use this code to set the stops
public void setNoStops(int stopsNo){ noOfStops = stopsNo; }
[code]...
The bottom written line of code is mentioned in the null pointer error I recieve. Then.Then in my main programme I declare the new object and use these methods the method options displays the list of five stations with a number reference
System.out.println("Please choose a start station :"); options(); place1 = scanner.nextInt(); System.out.println();
System.out.println("Please choose an end station :"); options(); place2 = scanner.nextInt(); System.out.println();
[code]...
mystops is the object I created to store the information.
when compiling I recieve no errors.when I run the program it runs smoothly, asks for the number of stops, allows the user to enter a number, then says enter stop 1, I enter a word and the program crashes giving the error java.lang.NullPointerException
I'm a complete beginner in Java programming and I'm interested to learn more about its concepts.
Recently, I've been given an exercise which instructs me to display two versions of a picture. The picture to be displayed is provided in the form of a data file of 40,000 digits that are arranged in rows (although there is no marker between rows) and it starts from the top of the picture. So the first digit represents the top left corner of the picture and the last is the bottom right.
Basically, what the exercise wants me to construct a program that plots a dot in one of two colours for each digit. If the digit is in the range 0 to 3 the output should be one colour and for digits in the range 4 to 9 the dot should be in the other colour.
I understand I have to use arrays and also loops to perform this. I'm familiar with the fillEllipse, drawEllipse, drawRectangle and fillRectangle but this exercise is nothing I've attempted before.
When out is equal to the String "2x2.5", the array operations ends up looking like this when it is printed using the toString method:
[, , , x]
As you can see, before the array element x, there are three String variables which only contain whitespace. Why does this occur, and how can I prevent this from happening?
Why is it not showing those months updated balance? I feel like I'm pretty close. I guess I should specify that this is supposed to calculate monthly interest for one account and quarterly interest for the other. This is what the output should look like.
I'm trying to make this code's output display like a sentence, since right now it displays downward and doesn' look right.
public class ReverseOrder { public static void main(String[] args) { String phrase = "The rain in Spain falls mainly on the Plain"; char[] phraseArray; phraseArray = phrase.toCharArray(); for(int i = phraseArray.length - 1; i >= 0; i--){ System.out.println(phraseArray[i]); } } // end main } // end ReverseOrder class
I've to read in an array of 1000 random numbers, and then my program sorts them depending on whether the user chooses bubblesort, selectionsort, etc...My code all works fine, my problem is with the actually output display. I have method that displays the content of the array that I call for the unsorted array, and for the sorted array. So at the moment the output to the user looks like:This program sorts an array of numbers by your choosing.
Array before sorting: 148 626 817 4 312 652 643 134 etc... for 1000 numbers
Write a program to create an integer array of size 20. Then, the program should generate and insert random integers between 1 and 5, inclusive into the array. Next, the program should print the array as output.
A tremor is defined as a point of movement to and fro. To simulate it, the program will generate a random number between 0 and 19, which represents the location in the array (i.e. index number). Then, the 3 numbers to the left and right of this location should be reset to the value 0. If there isn't 3 numbers to the left and right you may assume a lesser number depending on the boundaries of the array.
Then, the final array should be printed as output. There is no user input for this program.Your program must include, at least, the following methods:
-insertNumbers, which will take as input one integer array and store the random numbers in it. -createTremor, which will generate the random number as the location and return it.
I am working on a simple JAVA tutorial, not homework, where employee data is taken from an array and displayed on the console. The data is divided by department, age, name and for the Accounting and Information Systems departments, they are displayed in ascending order by employee age. Everything works except I am not getting the output to the console other than the titles. As I step through the debug, the data clearly is populating the array.
package SimpleJavaAssignment; import java.math.*; public class PrimeAgeChecker { public boolean PrimeAgeChecker(int age) { BigInteger bi = new BigInteger(String.valueOf(age)); boolean prime = bi.isProbablePrime(10); return prime; } }
I need comparing two array lists. For this program i am comparing 2 array lists. The list is integers entered by the user the second is random generated numbers. So far in my program i am able to compare the 2 arrays together and output if they are equal or not however i need the program to output even if atleast one if the integers match,
EXAMPLE list one: 1, 2 ,3 ,4, 5. LIST TWO: 1, 3, 3, 3, 3.
Since the first number matches i want it to out put there is one match, so on and so forth with if there are 3 or 4 matching integers. here is my code so far.
public static void main(String[] args) { final int NbrsEntered = 5; //Number of guessed numbers entered final int LOTTOnbr = 5; int[] numbers = new int[NbrsEntered]; int[] randomNum = new int[LOTTOnbr]; //int[] TestArrayOne = { 1, 2, 3, 4, 5 }; //int[] TestArrayTwo = { 1, 2, 3, 3, 5 }; boolean arraysEqual = true; int index = 0;
How do I put this code in a way that it works because I know it is probably something obvious but I cant find how to make the array readable without error. It is supposed to intake two values and output what day of the week it is.
Testing Program
Initial day: Monday Next day: Tuesday Next day again: Wednesday Previous day: Tuesday Next week: Tuesday Add 4 days from initial day: Friday
I am trying to make a game, for some reason i have begun to get a java.lang.StackOverflowError.
I am not exactly sure how i can fix it. only removing line 14 from infopannel1 (and everything that used that class.) seems to work. im not sure what else i can do to fix it. or why its resulting in stack overflow for that matter.
I am putting in a link for the files i wrote this using bluej (several classes have no relevance, errorv2, demonstration, folderreadertest, ReadWithScanner, saveloadtest, menutest,rannum, and menutestTester. are all irrelivent to my problem.)
public void myFunc(MyNode n, ArrayList<MyNode> path) { boolean hasChildren = false; path.add(n); int index = path.indexOf(n); ArrayList<MyNode> statefulPath = new ArrayList<MyNode>();
[Code] ....
I have similar code that I stepped through in a debugger. After running the code I found that it built the desired tree, in this case a root node H with left child L and right child P. I want list of lists to contain all paths from root to leaf. I expected [H, L] and [H, P]. I discovered that statefulPath is not stateful; after a recursive stack frame pops, statefulPath still contains n! But that stack frame just popped! I expected to see statefulPath be [H] in the debugger and it was [H, L]! So I later have a list [H,L,P] which I don't want. How do I make the statefulPath list I want for my algorithm?
