My program consists of a grid composed by a 2D array.
The user input deletes certain elements of the grid, leaving blank spaces.
My issue is making the elements above the blank spaces drop down.
Originaly I had an array to check if a space is blank, and if is was blank, the element above would be deleted and recreated where there used to be a blank.
My problem is, the array I used to do this was Left->Right, Top->Down (i++, j++), this leaves me with the problem of having to repeat the whole code to get newly built blank spaces. (For example, if I delete something from the 3rd row, the 2nd row would be blank, but I'd have checked the 2nd row already.
Since it would be very uneffective (including overstack errors) I decided to do the reserve, bottom->top, right->left array (i--,j--), my issue with this is that I'm getting an array out of bounds error, even though I made sure its not possible for it to go out of bounds.
Here is the piece of code which is giving problems
public static void dropBall(){
for (i =Settings.row-1;i>=0;i--){
for (j =Settings.col-1;i>=0 ; j--){
if (i <0||j<0)break;
if (Settings.grid[i+1][j]==666){
//checking if the space below has the 666 ID (666 ID equals to blank)
Settings.grid[i+1][j]=Settings.grid[i][j]; //Deleting the current blank
}
}
}
}
Note:
Settings.row and Settings.col are similar to something.lenght, meaning they have the lenght of the grid, even though the grid starts at 0.
How can I avoid the outofBounds error in this situation?
On line3:
for (j =Settings.col-1;i>=0 ; j--){
change to:
for (j =Settings.col-1;j>=0 ; j--){
and you can remove the if line after.
and start your i on Settings.row-2 instead
try this:
public static void dropBall(){
for (i =Settings.row-1;i>=0;i--){
for (j =Settings.col-1;j>=0 ; j--){
if (Settings.grid[i+1][j]==666){
//checking if the space below has the 666 ID (666 ID equals to blank)
Settings.grid[i+1][j]=Settings.grid[i][j]; //Deleting the current blank
Settings.grid[i][j] = 666;
}
}
}
}
Start from the second row at the bottom, and not from the first (since there is no row below it):
for (i = Settings.row-2 ... // instead of row-1
Remove this line (it is redundant):
if (i <0||j<0)break;
Related
I've been trying to get over a problem :
Let's say, you have an 3*4 (3 row 4 col) :
Let's take A[1][3] for example :
He's adjacent to the A[2][3], who is adjacent to A[2][2]
My goal, like the "SameGame" Game, is to find a way in order to have every adjacent similar characters' positions in an array in order to highlight them.
At first, I was thinking about doing a loop to check neighbors everytime I found some adjacent similar character, but it seems like a lot of pain for something like this.
if((this.tabi[x][y] == this.tabi[x+1][y])) {
this.group[x+1][y] = this.tabi[x+1][y];
this.group_size++;
// call it again for this.tabi[x+1][y]
}
}
Is there a more "performant-wise" solution ?
The board is generated randomly :
for (i=0; i<row; i++) {
for (j=0; j<col; j++) {
tab[i][j] = A OR B OR C
}
}
Thanks !
You could use a pathfinding algorithm like Dijkstra or Fjord-Warshall between two Group-Elements and treat every other group as an obstacle.
It's hard to tell, if you don't post a bit more about how you manage your playing field, elements and groups.
There is a table with application numbers and user data. at the beginning of the table, the application number at the end is a green arrow. There can be an infinite number of fields in a table and it always changes.
I need to find the green arrow by the application number and click on it accordingly.
tried to do something like
String myorder = "629/0000/000000021059";
if (myorder.equalsIgnoreCase(driver.findElement(By.xpath("/html/body/table/tbody/tr[1]/td[2]/div[2]/div/div[2]/div[2]/div/div/div/div/div[1]/table/tbody/tr/td[5]\n")).getText())){
driver.findElement(By.xpath("/html/body/table/tbody/tr[1]/td[2]/div[2]/div/div[2]/div[2]/div/div/div/div[1]/div[1]/table/tbody/tr/td[18]/a/img\n")).click();
} if (myorder.equalsIgnoreCase(driver.findElement(By.xpath("/html/body/table/tbody/tr[1]/td[2]/div[2]/div/div[2]/div[2]/div/div/div/div[1]/div[2]/table/tbody/tr/td[5]\n")).getText())) {
driver.findElement(By.xpath("/html/body/table/tbody/tr[1]/td[2]/div[2]/div/div[2]/div[2]/div/div/div/div[1]/div[2]/table/tbody/tr/td[18]/a/img\n")).click();
} if (myorder.equalsIgnoreCase(driver.findElement(By.xpath("/html/body/table/tbody/tr[1]/td[2]/div[2]/div/div[2]/div[2]/div/div/div/div[1]/div[3]/table/tbody/tr/td[5]\n")).getText())) {
driver.findElement(By.xpath("/html/body/table/tbody/tr[1]/td[2]/div[2]/div/div[2]/div[2]/div/div/div/div[1]/div[3]/table/tbody/tr/td[18]/a/img\n")).click();
and so on up to 100+
The first problem is that I really don't like the option of writing if else 100 times. And there is only one digit in the diva where the id of the application and one in the digit in the diva where the green arrow is different(img)
The second problem is that no matter how I insert break; when finding the right application, he clicks on the desired arrow, but after apparently trying to continue searching the page, but the page has already changed and the error falls
(WARNING: The server did not provide any stacktrace information)
if I use the code that was attached above or just an indication of the element (which goes right after the one that turned out to be correct and the page has changed) with a note that I can not find it, if I use else if with break;
tried to do so
for (int i = 1; i < 25; i++) {
String myorder = "629/6300/000000412067";
if (myorder.equalsIgnoreCase(driver.findElement(By.xpath("/html/body/table/tbody/tr[1]/td[2]/div[2]/div/div[2]/div[2]/div/div/div/div[1]/div["+ i++ +"]/table/tbody/tr/td[5]\n")).getText())) {
driver.findElement(By.xpath("/html/body/table/tbody/tr[1]/td[2]/div[2]/div/div[2]/div[2]/div/div/div/div[1]/div["+ i++ +"]/table/tbody/tr/td[18]/a/img\n")).click();
break;
}
But if the item is located, then it clicks on the very first arrow in the table, and not on the one in the same column as the application number
I would really appreciate your help!
XPaths are 1-based not 0, so you are correct in thinking you need to add one, however, these two are not equal as i++ modifies the value of i (even inline like you have it), which you do twice inside your loop. Therefore the 2nd iteration of your loop i will be 3, not 1 as expected. In your loop replace i++ with i + 1 and you should be good to go.
for (int i = 1; i < 25; i++) {
String myorder = "629/3500/000000329976";
if (myorder.equalsIgnoreCase(driver.findElement(By.xpath("/html/body/table/tbody/tr[1]/td[2]/div[2]/div/div[2]/div[2]/div/div/div/div[1]/div[" + i + 1 + "]/table/tbody/tr/td[5]\n")).getText())) {
driver.findElement(By.xpath("/html/body/table/tbody/tr[1]/td[2]/div[2]/div/div[2]/div[2]/div/div/div/div[1]/div[" + i + 1 + "]/table/tbody/tr/td[18]/a/img\n")).click();
break;
}
}
Unable to locate element: {"method":"xpath","selector":"/html/body/table/tbody/tr[1]/td[2]/div[2]/div/div[2]/div[2]/div/div/div/div[1]/div[31]/table/tbody/tr/td[5]
"}
So it was searching untill 31. And it's strange because i used for i < 25 and there are only 25 rows in the table.
but still dont work for me;(
I want to delete an index that consists of data: name, pass, and phone. At first, I used array.remove(index) method but it only worked if I only have one data. I have tried to use some formula too such as array.remove((index-1)*3) but when I chose show data, it all got messed up. I tried to use looping too but the end result also got messed up.
Is there any way or logic that I can implement to do that?
and this is my current code :
case 3:
show(menu);
System.out.println("Input data number to be deleted: ");
int index = scan.nextInt();
//menu.remove(index);
//menu.removeRange
for(int i = index-1, j = index ; i < menu.size(); i+=3, j++){
menu.remove(i);
menu.remove(j);
//System.out.println("Data is removed");
}
// menu.remove((index-1)*3);
// menu.remove((index-1)*3+1);
// menu.remove((index-1)*3+2);
System.out.println("Data is removed");
break;
}
It's a bit hard to work out what you are trying to do but I'm guessing your issue is that you are removing items from a collection using an index and ignoring the fact that removing one item moves the subsequent items forward.
In other words,
collection.remove(3);
collection.remove(3);
collection.remove(3);
Removes items that were originally at indices 3, 4 and 5
I am creating a game board. I need it to reveal a the selected column after a user input, while the rest of the columns still print as "X". This game holds values I have set in each column, but does not print them on the screen. When the user selects a column, I need it to print showing the value that column is holding while the rest of the columns still print "X" so they do not reveal what they have. I am new to this, thank you for your help.
This is the function where I think the problem is. If you look, you will see that I have the if statement "if (isCovered) - then I want it to print the covered version. Then the "else" - which is where I want it to print just the one that was guessed as its actual value. I have tried multiple ways of achieving this with no luck. Is there are way to make it like (!isCovered)? But that doesn't work, because it states it needs to be an array and the function "!" does not work. Right now it just seems like it never prints the "else" statement at all. I have functions that take the user input and compare them to "isCovered" and they work correctly, because the piece moves on the board as it should. I just cannot get it to print the actual value instead of an "X". Thank you for any help and if further information would be helpful, please let me know. It is due today unfortunately I only had a few days to work on it and have been working constantly on it.
public static void PrintRevealBoard(int[][] myArray,Boolean[][] isCovered)
{
int i, j;
for (i = 0; i<myArray.length ; i++ ) { // array.length = max rows
System.out.print((i+1) + " ");
for(j = 0; j <myArray[0].length; j++) { // array[0].length = max
cols
if(isCovered[i][j]){
System.out.print(GetRollColorCovered(myArray[i][j]) + " ");
} else {
System.out.print(GetRollColor(myArray[i][j]) + " ");
}
}
your main module is kinda messy. And I don't know how GetRollColor(dice) works. Anyway as I understand you have a two dimensional array and you want to show only a specific value. Seems like u want to show the entire input column.
use this to update isRevealed() after the input of inputCol.
public static Boolean[][] updateRevealed(Boolean[][] isRevealed, int inputCol){
for(int i=0;i<isRevealed[inputCol].length;i++)
isRevealed[inputCol][i] = true;
return isRevealed;
}
update like this,
isRevealed = updateRevealed(isRevealed,inputCol);
your printRevealBoard is almost correct. Just remove the first line. It doesn't make sense and you don't want it as I see
int isRevealed = inputCol;
I don't know how your array looks like. But because of the first for loop u will definitely get an
index out of bounds exception
loop runs until I becomes myarray.length. and in the next loop you access index I of myArray. Exception will be thrown if I=myArray.length. u gotta fix it. If any problem occurs lemme know.
thankyou
edit:
try this for printRevealBoard
public static void printRevealBoard(char[][] myarray , Boolean[] []isRevealed){
for(int i=0;i<myarray.length;i++){
for(int j=0;j<myarray[0].length;j++){
if (isRevealed[i][j]) System.out.print(myArray[i][j] + " ");
else System.out.print("* ");
}
System.out.println();
}
}
While working on some java project I encountered this peculiar error:
java.lang.IndexOutOfBoundsException: Index: 1, Size: 2
How can there be an index out of bounds exception? Index 1 means it tries to get the second element, Size 2 means there are 2 elements, so there shouldn't be a problem, no?
Context:
I have the following function:
public int howManyAgents(){
// cell is a class that can have 0 or multiple objects
// I get a list of cells that contain at least 1 agent
List<Cell> cellsWithAgents = getNonEmptyCells();
// initializing a counter
int agentsCount = 0;
for(int i=0; i<cellsWithAgents.size(); i++){
// For every cell in the list I add to the counter the number of
// agents that cell contains
agentsCount += cellsWithAgents.get(i).howManyAgents();
}
return agentsCount;
}
Now, the problem was that I got a null pointer exception at the line:
agentsCount += cellsWithAgents.get(i).howManyAgents();
I want to debug the code, but this function is called many times while the program is running and the null pointer exceptions comes up at different points in time (after 10 seconds after 1 minute after 5 minutes). So I tried to come up with a method to have e breakpoint when the cell is null so I came up with this code:
public int howManyAgents(){
// cell is a class that can have 0 or multiple objects
// I get a list of cells that contain at least 1 agent
List<Cell> cellsWithAgents = getNonEmptyCells();
// initializing a counter
int agentsCount = 0;
for(int i=0; i<cellsWithAgents.size(); i++){
int pass;
if (null == cellsWithAgents.get(i))
pass = 1; // breakpoint here
// For every cell in the list I add to the counter the number of
// agents that cell contains
agentsCount += cellsWithAgents.get(i).howManyAgents();
}
return agentsCount;
}
Of course, it is not the best method. The most logical way is jut to surround the code with try/catch and put the breakpoint there. The point is that the code above didn't work. It did not stop at the breakpoint but instead it threw the index out of bounds exceptions at the line:
if (null == cellsWithAgents.get(i))
Why? How can it be possible to throw an index out of bound exception if apparently the index is in bounds?
Edit: changed a mistake in copying the code
Update:
I have tried to see why the null pointer exception appears with a try/catch and put a breakpoint there. It seems that cellsWithAgents sometimes contains a null. This is, most probably because of concurrency as #rlinden stated.
About concurrency: there are some cells that can contain agents. There is a variable number of agents that can move between the cells. There is a special agent that tries to count how many moving agents there are (using this function).
So, only one agent (thread) can use this function, but multiple agents can modify cells (and thus mess with getNonEmptyCells() and howManyAgents() results).
Still, how it is possible to get index out of bounds with size 2 and index 1? It is not possible because of the concurrency, is it? Because only this thread can change the list cellsWithAgents. So, even if one of the elements in the list becomes null, the list still contains that number of pointers, so the size of the list cannot change. Or can it in some way that I miss?
And how can it be explained that the stack trace prints Index:1 Size: 2?
New Idea
Try changing the loop and see if the error persists:
int agentsCount = 0;
for(Cell cell : getNonEmptyCells()) {
if(cell != null) {
agentsCount += cell.howManyAgents();
} else {
System.out.println("Found a null cell");
}
}
I would like to see the code of the method getNonEmptyCells(). If your program is actually multithreaded and this function returns a fixed List that is changed at every interaction, then it is possible that changes in following executions have affected the previous, unfinished ones.
This is due to the fact that the line cellsWithAgents = getNonEmptyCells(); does not create a copy, but a reference to the return value of getNonEmptyCells(). So, if this method reuses the return object, it is possible that the first execution would believe there was two, but the concomitant thread changed the content size to less than 2.
The problem is, program is throwing exception at cellsWithType.get(i). What you can do is either put a breakpoint at if (null == cellsWithType.get(i)) and try debug it. Or change it to,
if (i >= cellsWithType.size())
pass = 1; // breakpoint here