Sam Acropolis

OMG , I totally missed that !! Forgot to create a splash.xml file in the layout folder!

Thank you so much man!

So I made this new Java Class called splash which will be used to display a background image in my app . I wrote a onCreate method and then added this line so the image can be referenced and be placed in the "background" .

setContentView(R.layout.splash);

the entire code in the Splash class:

protected void onCreate(Bundle SamGymRat) { // TODO Auto-generated method stub super.onCreate(SamGymRat); setContentView(R.layout.splash); }

The Error that complains on "splash" in setContentView

splash cannot be resolved or is not a field

I dont know if something has to be created in the R.Java file , from what I know its a no-no to touch that ...

any idea?

Thanks everyone

My package name is as you say it com.example.firstandroidproject;

Im pretty much creating a android virtual device and then attempting to launch it , I have even tried 'cleaning' the project to from the 'project' menu in eclipse.

Line 15 and 22 complain that

R cannot be resolved to a variable

I have tried removing the import android.R

statement and even renaming it to import com.HelloWorld.firstandroidproject.R;

but the syntax errors still persist ...

any ideas?


Thanks a bunch everyone


package com.example.firstandroidproject; import android.app.Activity; import android.os.Bundle; import android.view.Menu; public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //R.layout.activity_main } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.activity_main, menu); return true; } }

String s = ""; s += "Your orginal number: " + inputN + "\n\tYour new converted number: " + inputB; return s;

Ok I managed to come up with this and solves the recursion issue ... now the program seems to stop after the second prompt asking for the base to which to be converted .

Print out the numbers the user typed , their converted number and then return the toString. Maybe the return is causing the problem probably....

BaseConvert bc = new BaseConvert(); output = bc.toString();

This may be the culprit as to why their is a StackOverFlow

Thanks I think Im very close ..but the issue now is a StackOverFlow error so pretty much lines 92-95 repeated indefinitely.

Sorry for not explaining Im pretty much trying to pass the Input N and InputB Variables into my toString so they will grab the number to be converted and use the the "base" I have supplied and convert it to that , and the program will check
what base using the IF statements I have provided

Thanks

Hey Guys so I finished writing this basic program to convert a number to base 2-10 . I created the IF statements in the toString method, and to get the base convesion using Integer.toString(String s, baseToConvertTo) . My issues is I can define toString 'static' and have it execute from Main and I have tried sending inputB and inputB to the toString via inputB.toString() ...sorry noob in Java. Is there a way when I run the program after I have typed after the prompts I can access the method and it will return me my desired result?

Thanks

package com.Java.CS300; import java.util.Scanner; public class BaseConvert { private static int i; //variables static int inputN= i; static int inputB; static String output; //main program public static void main(String[] args) { DisplayInstructions() ; UserInput(); toString(); } //prompt the user public static void DisplayInstructions() { System.out.print("Hi Welcome to the base conversion program!\n"); } //end of DisplayInstructions //collect user input public static void UserInput() { //user input constructor Scanner user_input = new Scanner(System.in); //User Prompts begin System.out.println("\nPlease type the number you wish to convert here: "); int inputN; inputN=user_input.nextInt(); System.out.println("Please type the base you wish to convert into\n(Select a base between 2-10): "); int inputB; inputB = user_input.nextInt(); } // end of UserInput //converts and outputs the result public String toString() { inputN = i; if(inputB ==2) { Integer.toString(i, 2); } if(inputB ==3) { Integer.toString(i, 3); } if(inputB ==4) { Integer.toString(i, 4); } if(inputB == 5) { Integer.toString(i, 5); } if(inputB == 6) { Integer.toString(i, 6); } if(inputB == 7) { Integer.toString(i, 7); } if(inputB == 8) { Integer.toString(i, 8); } if(inputB ==9) { Integer.toString(i, 9); } if(inputB ==10) { Integer.toString(i, 10); } //tests System.out.println("You typed: " + inputN + " as your number!"); System.out.println("You typed: " + inputB + " as your base!"); System.out.println("Your new converted number!: "); return toString(); } }

Campbell Ritchie wrote:

Sam Acropolis wrote: . . . I wanted to pass parameters would I have to define a new . . . method up above?

Yes. But what does “up above” mean?

good question in more detail would defining a new method after :

private class cs340ListIterator implements ListIterator<E>

work? Or does it go into the superclass(the class above the ListIterator subclass)

ohhh I see wow I totally missed that...but what If I wanted to pass parameters would I have to define a new remove method up above?

alright so Im working on a double linked list and writing a remove method which passes in a argument and throws a illegalStateException if there is no value passed into the variable lastItemReturned (which it has its a check)

my issue I cant seem to fix the error: "method does not override or implement a method from a supertype"

issue is at the public void remove(E remove) method and at the subclass cs340ListIterator which I get: cs340DLL.cs340ListIterator is not abstract and does not override abstract method remove() in ListIterator

am I not implementing the interface correctly and instead in the remove() method do

throw new IllegalStateException();

here is the class file:

package cs340.edu.util; import java.util.ListIterator; import java.util.NoSuchElementException; public class cs340DLL<E> { private Node<E> head = null; private Node<E> tail = null; private int size = 0; private static class Node<E> { private E data; private Node<E> next = null; private Node<E> prev = null; private Node(E dataItem){ data = dataItem; } } public void add(int index, E obj){ this.listIterator(index).add(obj); } public ListIterator<E> listIterator(int index){ return new cs340ListIterator(index); } public E get(int index){ return listIterator(index).next(); } private class cs340ListIterator implements ListIterator<E> { private Node<E> nextItem; private Node<E> lastItemReturned; private int index = 0; public cs340ListIterator(int index){ if (index < 0 || index > size){ throw new IndexOutOfBoundsException("Invalid index " + index); } lastItemReturned = null; if(index == size){ this.index = size; nextItem = null; } else{ nextItem = head; for(this.index = 0; this.index < index; this.index++){ nextItem = nextItem.next; } } } @Override public void add(E data) { // Add to empty list if(head == null){ head = new Node<E>(data); tail = head; } //Insert at head else if(nextItem == head){ Node<E> newNode = new Node<E>(data); newNode.next = nextItem; nextItem.prev = newNode; head = newNode; } //Insert at tail else if(nextItem == null){ Node<E> newNode = new Node<E>(data); tail.next = newNode; newNode.prev = tail; tail = newNode; } //Insert in the middle else { Node<E> newNode = new Node<E>(data); newNode.prev = nextItem.prev; nextItem.prev.next = newNode; newNode.next = nextItem; nextItem.prev = newNode; System.out.println("Adding middle " +data); } size++; index++; lastItemReturned = null; } @Override public boolean hasNext() { return nextItem != null; } @Override public boolean hasPrevious() { return (nextItem.prev != null) || (nextItem == null && size != 0); } @Override public E next() { if(!hasNext()){ throw new NoSuchElementException(); } lastItemReturned = nextItem; nextItem = nextItem.next; index++; return lastItemReturned.data; } @Override public int nextIndex() { // TODO Auto-generated method stub return 0; } @Override public E previous() { if(!hasPrevious()){ throw new NoSuchElementException(); } if(nextItem == null){ // iterator past last item nextItem = tail; } else{ nextItem = nextItem.prev; } lastItemReturned = nextItem; index--; return lastItemReturned.data; } @Override public int previousIndex() { // TODO Auto-generated method stub return 0; } // @Override // public void remove(E data) // { // // } // end of remove method @Override public void remove(E remove) { if(lastItemReturned == null) { throw new IllegalStateException("Error! There is no value in lastItemReturned!"); } } @Override public void set(E e) { throw new IllegalStateException("Not supported yet."); } } // @Override // public void set(E e) { // // TODO Auto-generated method stub // // } public String toString() { Node<E> nodeRef = head; StringBuilder result = new StringBuilder(); while (nodeRef != null){ result.append(nodeRef.data); if(nodeRef.next != null) { result.append(" <==> "); } // end of if loop nodeRef = nodeRef.next; } // end of while loop return result.toString(); } // end of ToString method } // end of CS340DLL class

any pointers ?

thanks guys as always

Do you know of any good material on the web on Algorithms since my book doesnt go too much into it . I would love to sit down and read a whole bunch on this

@fred rosenberger lol I actually figured it out this morning for some reason when you said "this is pretty straight forward" I was like Hmmm and then Eureka!

I have a book but it just scratches the surface in the algorithm concepts.

Thanks for the pointers!

Im working on some problems on Algorithmic complexities would really love if someone just pointed me in the right direction:

I couple questions:

1.) Prove the following using the formal definition of Big-Oh complexity
a.) Prove that if an algorithm has: simple operations, then its complexity is: <-- honestly i don't know what this is asking .


2.) int[] anArray = {0,1,2,3,4,5,6,7}; for(int i = 3; i < anArray.length - 1; i++) anArray[i+1] = anArray[i];

for this one the variable 'i' is initialized to 3 and then the length is shifted over by "1" and then in the body the array index is shifted to the "right" and whatever value that is , is assigned to the index? Am I correct if so would that give me the contents of anArray after the loop executes?



3.) This one went way over my head:

Determine algorithmic complexity in terms on n .
How would I even start this ?


result = 0; for(i = 0; i <1000;i++) { result++; }