Johnny Steele

got it!!! I figured it out. thanks!!!

Hi,

Im trying to build a method that adds a node to this tree. It takes arguments, a number representing the order at which this node needs to be placed in the tree, and the element that the node is to contain.

so for example,

..............25
............./...\
.........16......50
......./...\.........\
...14....20........75

so if I were to add the number 30 it would be at 50.left

if there is a matching duplicate number, I have to return the element of the node being replaced.

this is what I have so far...
its not wright but its a start.
I'm getting nullPointerExceptions on my tests so far.

any advice?
public V put(K key, V newValue) { MapNode current = root; MapNode previous = root; MapNode temp; while(current != null) { if(key.compareTo(current.key) < 0) { previous = current; current = current.left; }else if(key.compareTo(current.key) > 0){ previous = current; current = current.right; }else if(key.equals(current.key)){ temp = current; current = new MapNode(key, newValue); return temp.value; } } current = new MapNode(key, newValue); return null; }
thanks

thanks! But how would I do the same thing without decimalFormat using toString?

Hi!

I'm creating a method that inserts commas in an integer given as an argument and returns it as a string with the commas inserted in the propor places. I have the following but does anyone have any ideas as to how I can do this without importing decimal format, like with toString or the like?

public String comma(int n) { DecimalFormat a = new DecimalFormat("#,###"); String b = ""; b = a.format(n); return b;

that seems to work!!! thank you very much!!! I did not think to use a for loop as in the past we've been told to avoid loops but not with this one.

thanks a lot!!!

my assignment requires it to be witten using recursion.

Hi,

Who loves recursion?!?!?!?!

So, given an array of ints I need to recursively find the number of times a particular integer appears in that array. Like so:

public int numOf(int number, int[]a) { int index = 0; int count = 0; if(x.length > 0) { if(index < x.length) { if(number == x[index]) { count+= +1; index+= +1; return count + index + numOf(number, a); }else{ index += +1; return count + index + numOf(number, a); } }else{ return count; } }else{ return 0; }

This code is creating a huge stackOverFlow error when I unit test it. I am at a loss. I am allowed to use private helper methods although I am a bit confused as to how that would help in general or particular to this case. Regardless, any suggestions?

Thank you much

I found that I had to instantiate all the variables in the private class. Took me a while to figure out!!!

public MineSweeper(boolean[][] mines) { board = new GameSquare[mines.length][mines[0].length]; for (int row = 0; row < mines.length; row++ ) { for (int col = 0; col < mines[row].length; col++ ) { board[row][col] = new GameSquare(mines[row][col] , row, col); } }

hey everyone. So i'm working on my own version of mineSweeper. My professor's explanation, even after several times asking, doesn't seem to quite click with me. In the following code, I have to implement the MineSweeper constructor and my needed instance variable in it. So I've been told the constructor is taking an array of GameSquare objects. My question is: how do I initialize the information within each object if the GameSquare class if Private? Then, how do I call this array later in order to set the my other methods such as isFlagged, click, and so on? Just need a push in the right direction and some clarity, I'm quite confused. Thanks!!! Oh, this method is being implemented in such a way so that I can do some unit testing. There is another constructor using a random number generator but I believe the point of this one is testing.
public class MineSweeper { private class GameSquare { private boolean isMine; private int row; private int col; private boolean isVisible; private boolean isFlagged; private int mineNeighbors; // Construct a GameSquare object with all values set except mineNeighbors public GameSquare(boolean isMine, int row, int col) { this.isMine = isMine; this.row = row; this.col = col; isVisible = false; isFlagged = false; mineNeighbors = 0; // Use setAdjacentMines to set this instance variable } // After determining the number of mines around any GameSquare, set the number of surrounding mines private void setAdjacentMines(int neighborCount) { this.mineNeighbors = neighborCount; } } // Represent all GameSquare objects where each knows its row, column, // number of mines around it, if it is a mine, flagged. and visible private GameSquare[][] board; /** * Construct a MineSweeper object using a given mine field represented by an * array of boolean values: true means there is mine, false means there is not * a mine at that location. * * @param mines * A 2D array to represent a mine field so all methods can be tested * with no random placements. */ public MineSweeper(boolean[][] mines) { // TODO: Complete this constructor first so you get a copy of a preset mine // field stored in this object. Develop your own private inner class named // GameSquare to store all info about one square on the board such as row, // column, if it's flagged, visible, or is a mine. Also storing the // number of adjacent mines around each GameSquare should be done here. int neighbors; for (int row = 0; row < mines.length; row++ ) { for (int col = 0; col < mines[row].length; col++ ) { board = mines[row][col]; } neighbors = getAdjacentMines(row, col); board.setAdjacentMines(neighbors); } } }

as you can see I started but have no idea what i''m doing.
-Thank you ahead of time.

Thanks. Sorry about posting this twice. i know to use "\n" but as of now I cannot use StringBuilder. I'm just not sure how or where to put "\n" in order to get the desired diagonal printed.
Thanks again for the response,
-john

Hi! I'm working on a method that takes in an array called number and returns its contents to be printed in a diagonal like so:
16 17 98 97 95 -14 -15 99
with tabs in between and each element printed on a new line.
Here is my method which is obviously very wrong but its what I have.
public String diagonal() { String done = ""; for( int i = 0; i < number.length; i++ ) { for( int j = 0; i < number.length; i++ ) { done = done + number[i] + "\t"; } return done; }
Just cant figure out how to incorporate the new line into a loop or object for that matter.
Thanks,
-John

Hi! I'm working on a method that takes in an array called number and returns its contents to be printed in a diagonal like so:
16 17 98 97 95 -14 -15 99
with tabs in between and each element printed on a new line.
Here is my method which is obviously very wrong but its what I have.
public String diagonal() { String done = ""; for( int i = 0; i < number.length; i++ ) { for( int j = 0; i < number.length; i++ ) { done = done + number[i] + "\t"; } return done; }
Just cant figure out how to incorporate the new line into a loop or object for that matter.
Thanks,