Jefferey Stevens

Hi, I need to test the methods in this code. In the Main method I need to create a list of strings of however many I want, ex 5, and then test the methods in the code provided, except the iterator one. I also need to be able to print the list, iteratively somehow? I just can't figure out how to start the main, would someone be able to give me an example of how to test one of the methods? I could probably figure the rest out then. Thanks!

package edu.nps.util; public class NPSLinkedList<E> implements NPSList<E> { public static final int NOT_FOUND = -1; private ListNode head; private ListNode tail; private int count; public static void main(String [] args){ } public NPSLinkedList( ) { clear( ); } public void add(E item) { //creates a new ListNode ListNode newNode = new ListNode(item); if (count == 0) { head = tail = newNode; } else { tail.next = newNode; tail = newNode; } count++; } public void add(int index, E item) throws IndexOutOfBoundsException { checkInsertPosition(index); ListNode ptr = head; ListNode newNode = new ListNode(item); if (index == 0) { //adding the new node as the first node newNode.next = head; head = newNode; } else { for (int i = 1; i < index; i++) { ptr = ptr.next; } newNode.next = ptr.next; ptr.next = newNode; } //adjust tail if the new node added is //the last node in the list if (index == count) { tail = newNode; } count++; } public void clear( ) { head = tail = null; count = 0; } public boolean contains(E item) { boolean result = true; int loc = indexOf(item); if (loc == NOT_FOUND) { result = false; } return result; } public E get(int index) throws IndexOutOfBoundsException { checkAccessPosition(index); E item = null; ListNode ptr = head; for (int i = 0; i < index; i++) { ptr = ptr.next; } item = ptr.item; return item; } public int indexOf(E item) { int loc = 0; ListNode ptr = head; while (loc < count && !ptr.item.equals(item)) { loc++; ptr = ptr.next; } if (loc == count) { loc = NOT_FOUND; } return loc; } public NPSIterator<E> iterator( ) { return new MyIterator(); } public boolean isEmpty( ) { return (count == 0); } public E remove(int index) throws IndexOutOfBoundsException { checkAccessPosition(index); ListNode deleteNode; ListNode ptr = head; if (index == 0) { //removing the first node deleteNode = ptr; head = head.next; if (head == null) { //removed first node is the only node tail = null; } } else { for (int i = 1; i < index; i++) { ptr = ptr.next; } deleteNode = ptr.next; ptr.next = deleteNode.next; if (ptr.next == null) { //very last node was removed tail = ptr; //we have a new last node } } count--; return deleteNode.item; } public boolean remove(E item) { boolean result = false; ListNode ptr = head; ListNode trail = null; while (ptr != null && !ptr.item.equals(item)) { trail = ptr; ptr = ptr.next; } if (ptr != null) { //found item if (trail == null) { //removing the first node head = head.next; if (head == null) { //removed first node is the only node tail = null; } } else { trail.next = ptr.next; if (trail.next == null) { //very last node was removed, so tail = trail; //set tail points to a new last node } } result = true; count--; } return result; } public E set(int index, E item) { checkAccessPosition(index); ListNode ptr = head; for (int i = 0; i < index; i++) { ptr = ptr.next; } E old = ptr.item; ptr.item = item; return old; } public int size( ) { return count; } /** * Checks the passed index position is a valid index that refers * to a non-empty position * * @param index value to check for valid position * * @exception IndexOutOfBoundsException if the passed index * is outside of the range of valid access positions */ private void checkAccessPosition(int index) { if (size() == 0) { throw new IndexOutOfBoundsException( "Index " + index + " is invalid. List is empty."); } else if (index < 0) { throw new IndexOutOfBoundsException( "Negative index of " + index + " is invalid"); } else if (index > size()-1) { throw new IndexOutOfBoundsException(index + " is larger than valid upper bound" + (size()-1)); } } /** * Checks the passed index position is a valid insertion point in * the array. * * @param index value to check for insertion position * * @exception IndexOutOfBoundsException if the passed index * is outside of the range of valid insertion positions */ private void checkInsertPosition(int index) { if (index < 0) { throw new IndexOutOfBoundsException( "Negative index of " + index + " is invalid"); } else if (index > size()) { throw new IndexOutOfBoundsException(index + " is larger than valid upper bound" + size()); } } // Inner Class: ListNode class ListNode { private E item; private ListNode next; public ListNode(E item) { this.item = item; this.next = null; } } ///---------- Inner Class : MyIterator -------------//// private class MyIterator implements NPSIterator<E> { private ListNode current; public MyIterator( ) { current = head; } public boolean hasNext( ) { return (current != null) ; } public E next( ) throws NPSNoSuchElementException { if (current == null) { throw new NPSNoSuchElementException(); } else { E item = current.item; current = current.next; return item; } } } }

I also posted here, http://www.java-forums.org/new-java/83655-linkedlist-question.html#post362584

I've realized that the second list is sorted, there are just no spaces between the double digit numbers. I can't think of any way to add spaces between the numbers.

I'm trying to write a program that generates 100 random number, prints them, then sorts them, then prints out the sorted list with ten numbers in each line. I cannot figure out what is wrong with my code. Anyone have any ideas? A detailed explanation would be awesome as I am new to this. This is what I have so far.

public class Main { public static void main(String[]Args) { int [] b; b = new int[100]; loadArray(b); printArray(b); Sort(b); printArray(b); } public static void loadArray(int[] b) { for(int i = 0; i < b.length; i++){ b[i]= (int)((Math.random())*100)+1;{ } } } public static void printArray(int[] b){ System.out.println(); for(int i = 0; i < b.length; i++){ System.out.print(b[i]); if((i + 1)%10 == 0) System.out.println(); } } public static void Sort(int [] b) { int Temp = 0; for (int i = 0; i < b.length-1; i++) { for (int j = i + 1; j < b.length; j++) { if (b[i]> b[j]) { Temp = b[i]; b[i] = b[j]; b[j] = Temp; } } } } }

And here is an example of what it prints out right now.

42629035334048469325
21775561975248917456
9340882010067304331
5542393117952289996
3775521286392295798
83166760847191818556
696337363376546310037
99637451574393191
54155896825250881413
4479358294746523

1244455688
9111213141516202123
23252829293031313333
35363737373739394040
42434546474848505252
52525454545556565757
58586061626363676769
71747475767779818283
84858688909191919393
9393969696979899100100

As you can see all of the lines have more than 10 numbers in them except for the first line of the sorted list, which is also the only line that is sorted. Any help would be appreciated, thanks.

Paul Clapham wrote:So, again breaking that task down into smaller pieces, would that mean that you don't know how to use a JOptionPane to input something? Or is it the inputting of a number that's giving you the problem? Or inputting 32 numbers?

All of it :[

JOptionPane.showInputDialogue?
I really have no idea how to go about it.

Okay, I'm not sure how to use JOptionPane to input two lists of 32 numbers in the Load method. I don't know how to start.

public static void Load(int [] A) { int [] Low = new int[31]; int [] High = new int [31]; int i = 0; while (i < Low.length){ JOptionPane? }

I'm trying to use the JOptionPane and a while loop to input two lists ( so two arrays?) of 32 numbers, which are made up by the user. The data cannot be sorted before it is entered into the arrays. It is supposed to ignore the numbers -1000 and 1000. I need to be able to print the average high and average low of the numbers and lows or highs position in order with the day( the index of the array?). I'm new at this so any help is appreciated. Here's what I have so far.

import java.util.*; public class rainfall { public static int[] Low; public static int[] High; public static void main(String[] args) { Init(); Print(); Load(); } public static void Init() { Low = new int[32]; High = new int[32]; for (int i = 1; i <= 31; i++){ Low[i] = 1000; High[i] = -1000; } public static void Load(int [] A) { int [] Low = new int[31]; int [] High = new int [31]; int i = 0; while (i < Low.length){ JOptionPane? } public static void Print() { } } } }

I am trying to write a method to calculate a value raised to an integer power (which I think is now correct). I need to display all the sines ( out to six decimal places, I assume you would use df.format?) for the angles 0 to 90 and also display the Math.sin values for the same angles. What I have written so far displays Sine of 1=0, Sine of 2=-0, up to sine of 67 where it says Sine of 76=?. I just need to figure out how to get it to display the sine values correctly. I am using eclipse and displaying in the console if that matters. Any help is appreciated! Thanks!

Someone also said, "I'm not familiar with the equation you're using to calculate sine but I think I can see why you keep getting 0.
You initialize "ans" with the value with 0, and then then you do ans = ans * term. But the value of ans is 0 so you are always multiplying "term" by 0, then setting "ans" equal to that value (which is always 0)."
Does anyone know how to fix it?

This is what i have so far,

import java.text.DecimalFormat; public class MyMath { public static void main(String[] args) { // test methods here for (int j = 0; j <= 90; j ++) { System.out.println( j + " factorial is " + Factorial(j)); } for(int i=0;i<=90;i++) { DecimalFormat df = new DecimalFormat("#.######"); System.out.println("Sine of "+i+"="+ df.format(Sine((double)i))); } } public static double Sine(double x) { //setup for loop double ans = 0; double term = x; int n = 1; //the while loop while ( Math.abs(term) > 0.0000001 ) { //do work ans = ans * term; //get ready inc n, calc term n++; term = Pow(-1,n+1)* Pow(x, 2*n - 1)/Factorial(2*n - 1); } //return ans return ans; } public static double Factorial(int n) { if (n < 0) { return -1.0; } double ans = 1.0; for(int i = 1; i <= n; i++) { ans = ans * i; } return ans; } public static double Pow(double base, int n) { if(base==0.0) //if the base is 0 return 0 return 0.0; if(n==0) //if the power is 0, then the result will always be 1 return 1; double answer = base; //Otherwise, set answer equal to base and multiply the base by answer n-1 times. for(int i=1;i<n;i++) answer*=base; return answer; } }