I'm making the connect 4 game in Java and in vs computer mode. The computer will play randomly. I wrote the code to select randomly the column. Computer does play randomly on a column but keep on playing on same column after.
How should I do to make it play randomly on any column whenever its computer's turn.
This is my simple code so far:
public static Random rnd = new Random();
public static final int row = Row - 1;
public static int col = rnd.nextInt(7);
What code should I write and I need the variable col for my next method of this class
You need to call nextInt each time the computer plays, to regenerate a random number.
What you currently have will generate a random number for the column but you never update it. So for each new game, the computer will play only in the same "random" column.
Let's say you have a method computerTurn() that you calls each time it's the turn of the computer to play. So something like that.
void computerTurn(){
int col = rnd.nextInt(7);
placeInCol(compute, col);
}
Note that you will have to check that you can play in the column. So the best way to deal with this is to create a List that will contains the column available to play.
List<Integer> columnsAvailable = new ArrayList<>(Arrays.asList(1,2,3,4,5,6));
Now it will look for something like this:
void computerTurn(){
int index = rnd.nextInt(columnsAvailable.size());
int col = columnsAvailable.get(index);
if(isAvailableCol(col)){
placeInCol(computer, col);
} else {
columnsAvailable.remove(index);
//get a new random column here.
}
}
The random number generated may repeat.That is the problem.So, you can save the generated random number temporarily , and check it with the next random number , if they are same loop it again.This is a wide logic. You can use Collections.shuffle(); . Then , there will be no head ache regarding repeatation.
Related
So well I tried creating a simpler Minesweeper game and I encountered one main problem..
I am not able to count the number of bombs and print it in a JTextField
Any ideas as to how to count these as I'm setting a random value to check whether they are a bomb
Tried counting it in the ActionListener but the bombs were counted only after the button was clicked.
if(e.getSource()==b[i][j])
{
b[i][j].setVisible(false);
tf[i][j].setVisible(true);
int r1 = rand.nextInt(6);
if(r1>1)
{
tf[i][j].setText("Safe");
tf[i][j].setBackground(Color.green);
}
else
{ count++;
tf[i][j].setText("Bomb");
tf[i][j].setBackground(Color.red);
f.setVisible(false);
restart.setVisible(true);
}
}
As I understand you decide if the the tile will be a bomb in the run-time using a random generator. Doing this you can't really know how many mines are in your game. I think you should decide the number of mines at the beginning of the game and randomly place them to your game board (you can choose the number according to a difficulty level).
EDIT
You can create a list with some random points that contain the mines
int numOfMines = 10;
int rows=5,columns=5;
ArrayList listWithMines = new ArrayList();
while(listWithMines.size()<numOfMines) {
int randRow = random.nextInt(rows);
int randCol = random.nextInt(columns);
Point point = new Point(randRow, randCol);
if(listWithMines.contains(point))
continue;
else
listWithMines.add(point);
}
This list now contains the Points that have the mines.
You can check if Point(x,y) has a mine like this:
if(listWithMines.contains(new Point(1, 2))) {...}
Instead of a list you can use a 2D array, store a boolean value (or int if you store more states) and make a loop until you place 10 mines. You should keep a counter(placedMines like the list.size()) of the mines you placed and make sure you don't add a mine to a tile that has already a mine and you increase the counter(placedMines) until it reaches the numOfMines.
So I'm working on a program which is supposed to randomly put people in 6 rooms (final input is the list of rooms with who is in each room). So I figured out how to do all that.
//this is the main sorting sequence:
for (int srtM = 0; srtM < Guys.length; srtM++) {
done = false;
People newMove = Guys[srtM]; //Guys is an array of People
while (!done) {
newMove.rndRoom(); //sets random number from 4 to 6
if (newMove.getRoom() == 4 && !room4.isFull()) {
room4.add(newMove); //adds person into the room4 object rList
done = true;
} else if (newMove.getRoom() == 5 && !room5.isFull()) {
room5.add(newMove);
done = true;
} else if (newMove.getRoom() == 6 && !room6.isFull()) {
room6.add(newMove);
done = true;
}
}
The problem now is that the code for reasons I don't completely understand (something with the way I wrote it here) is hardly random. It seems the same people are put into the same rooms almost every time I run the program. For example me, I'm almost always put by this program into room 6 together with another one friend (interestingly, we're both at the end of the Guys array). So how can I make it "truly" random? Or a lot more random than it is now?
Thanks in advance!
Forgot to mention that "rndRoom()" does indeed use the standard Random method (for 4-6) in the background:
public int rndRoom() {
if (this.gender == 'M') {
this.room = (rnd.nextInt((6 - 4) + 1)) + 4;
}
if (this.gender == 'F') {
this.room = (rnd.nextInt(((3 - 1) + 1))) + 1;
}
return this.room;
}
if you want it to be more random try doing something with the Random method, do something like this:
Random random = new Random();
for (int i = 0; i < 6; i++)
{
int roomChoice = random.nextInt(5) + 1;
roomChoice += 1;
}
of course this is not exactly the code you will want to use, this is just an example of how to use the Random method, change it to how you want to use it.
Also, the reason I did random.nextInt(5) + 1; is because if random.nextInt(5) + 1; gets you a random number from 0 to 5, so if you want a number from 1 to 6 you have to add 1, pretty self explanatory.
On another note, to get "truly" random is not as easy as it seems, when you generate a "random" number it will use something called Pseudo random number generation, this, is basically these programs produce endless strings of single-digit numbers, usually in base 10, known as the decimal system. When large samples of pseudo-random numbers are taken, each of the 10 digits in the set {0,1,2,3,4,5,6,7,8,9} occurs with equal frequency, even though they are not evenly distributed in the sequence.
There might be something wrong with code you didn't post.
I've build a working example with what your classes might be, and it is distributing pretty randomly:
http://pastebin.com/u8sZRxi6
OK so I figured out why the results don't seem very random. So the room sorter works based on an alphabetical people list of 18 guys. There are only 3 guy rooms (rooms 4, 5 and 6) So each guy has a 1 in 3 chance to be put in say, room 6. But each person could only possibly be in 2 of the 6 spots in each room (depending on where they are in the list).
The first two people for example, could each only be in either the first or second spot of each room. By "spot" I mean their place in the room list which is printed in the end. Me on the other hand am second last on the list, so at that point I could only be in either the last or second last spot of each room.
Sorry if it's confusing but I figured out this is the reason the generated room lists don't appear very random - it's because only the same few people could be put in each room spot every time. The lists are random though, it's just the order in which people appear in each list which is not random.
So in order to make the lists look more random I had to make people's positions in the room random too. So the way I solved this is by adding a shuffler action which mixes the Person arrays:
public static void shuffle(Person[] arr) {
Random rgen = new Random();
for (int i = 0; i < arr.length; i++) {
int randPos = rgen.nextInt(arr.length);
Person tmp = arr[i];
arr[i] = arr[randPos];
arr[randPos] = tmp;
}
}
TL;DR the generated room lists were random - but since the order of the people that got put into the rooms wasn't random the results didn't look very random. In order to solve this I shuffled the Person arrays.
Hello I am trying to create a method in Java that Accepts an integer from the user. Calculate and display how many occurences of the integer are in the array(i'm Creating a random array) as well as what percentage of the array values is the entered integer.
This is how i create my Array:
public void fillVector ( )
{
int myarray[] = new int [10];
for (int i = 0 ; i < 10 ; i++)
{
myarray [i] = (int) (Math.random () * 10);
}
}
Any sugestions how can i do to accomplish this ?
This seems like a homework to you so I am not gonna give you the full solution but I will break down the steps of what you need to do in order to solve your problem. You have to find out how to code those steps yourself, or at least provide some code and your specific problem because your question is too vague right now.
Ask the user to input the number.
Store that number somewhere.
Check each cell of the array for that number. If you find one appearance
increase the counter and continue until the end of your index.
Print out the appearances of the given number.
Print out the percentage of the cells containing the given value to the total amount of cells.
As I can see from your code (if it's yours) you are capable to pull this off on your own. It shouldn't be too hard.
static int n = -1;
private static int repeatBuffer[] = new int[10];
static {
repeatBuffer[0] = 0;
//and more
repeatBuffer[9] = 9;
}
static public void randomize() {
do {
Random r = new Random();
randomNumber = r.nextInt(20);
} while (!uniqueInt(randomNumber));
Log.e(TAG, "" + randomNumber); //here I need have a unique int
}
private static Boolean uniqueInt(int random) {
for (int i = 0; i < 9; i++) {
if (random == repeatBuffer[i]) {
return false;
}
}
if (++n > 9)
n = 0;
repeatBuffer[n] = random;
return true;
}
Sometimes I'm getting same int twice, I'm wondering where is the problem? And is it even work? I spend quite a lot of time on this, and I give up. I think I need some minor tweaks in code :)
An easier way to get a random int is to create a List of integers List<Integer>, adding it with numbers that you would like to have. Then shuffling the List using Collections.shuffle(list);. Now start reading from the beginning of the list and you will get a unique random int each time.
Just make sure that each time you "read" a number from the list, either remove it from the list or increase the index for where you read.
That's the normal behavior of a random number generator, it's correct to generate repeated numbers as long as the number distribution remains uniform.
If you need a set of unique random numbers, you can generate them inside a loop and ask at every iteration if the newly generated number is present in the set of generated numbers. If not, add it, if yes, keep iterating - until the set has the desired size.
Er, a unique random between 1 and 20? What happens when it runs the 21st time?
Try making a List of the Integers between 1 and 20. Use Collections.shuffle() to shuffle the list. Then pop the first item off the front of the list and use that.
I created two methods for my Bingo Game in Java. One method creates a new board which populates the Bingo Board with integers according to the Bingo rule (1-75). My second method generates random numbers with a range of 1 - 75.
public static int drawNum(){
Random rand = new Random();
int num = rand.nextInt(75)+1;
return num;
}
public static void bingoCard(){
int [][]card=new int [5][5];
ArrayList<Integer> alreadyUsed = new ArrayList<Integer>();
boolean valid = false;
int tmp = 0;
for(int i = 0; i <= 4; i++){
for(int row = 0; row < card.length; row++){
while(!valid){
tmp = (int)(Math.random() * 15) + 1 + 15 * i;
if(!alreadyUsed.contains(tmp)){
valid = true;
alreadyUsed.add(tmp);
}
}
card[row][i] = tmp;
valid = false;
}
}
card[2][2] = 0;
//create array to make title.
String title []={"B","I","N","G","O"};
for(int i=0;i<title.length;i++){
System.out.print(title[i]+ "\t");
}
System.out.println();
for(int row=0;row<card.length;row++){
for(int col=0;col<card[row].length;col++){
System.out.print(card[row][col]+ "\t");
}
System.out.println();
}
}
What I need help with is, how do I check whether or not the drawNum() method corresponds to any values stored inside my bingoCard() array? If so, print out a new array with the integers filled in. If the condition is met for a bingo, then you win.
I hope I don't make it sound like I want you to do it for me, but I am confused as to how to start coding that part. Thank you.
This my recommendation - Learn Object Oriented Programming immediately
I see you are using objects provided in the JDK, so why not learn to make your own?
Make two classes with the following methods (-) and members (+) (PS. This is not a formal way to document code)
BingoCard
+list of numbers on card
-reset() : gets new numbers for this card
-test(BingoDrawer) : Tests to see if this card won on this drawing
-toString() : returns a String representation of this card
BingoDrawer
+list of numbers drawn
-reset() : draws new numbers
-hasNumber(int number) : tests if this number was drawn
-toString() : returns a String representation of this drawing
One more suggestions
Instead of keeping track of what you used, keep track of what you have not used, it will make things much easier because you can just choose stuff from that list randomly. Unlike your current action which is choosing (a logical number) from thin air and hoping (which causes issues) it is not a collision
If you follow my recommendation you can write code like this
public static void main(String[] args) {
BingoCard bc = new BingoCard();
BingoDrawer bd = new BingoDrawer();
while(thePlayerWantsToPlay()) { //function to be defined by you
bc.reset();
bd.reset();
System.out.println(bc);
System.out.println(bd);
System.out.println(bc.test(bd));
}
}
You can take it a step further and make a BingoGame class and do what I did in main there and just create an instance of BingoGame and call some start method on the object.
For checking if you have the number in your board, read through the board in a similar manner as you do for the already_used numbers, except with the number the user just entered.
The conditions for the user to win should be checked after the board has another number guessed.
There are a few ways to do this, a simple one would be to iterate over every possible pattern that could win, checking to see if there are tokens there.
All of this would be in a loop, that goes a little like this:
Set up board via user entering numbers.
Start loop
set either a timer to wait for, or wait for a keypress (so the game doesn't just play really fast)
Get random number
Possibly add to board
Check if winner
if winner, break the loop and do something else.
Print the new board out.
(end of loop)
If they got here, that could mean they won!
Wait to exit
You can just write it out as pseudo-code and fill in the methods after that. It usually helps to work on these things in a top-down fashion. So, for bingo you might have:
board = generateBoard();
while (!bingoFound(board)) {
number = drawNumber();
board = stampNumbers(board, number);
}
If that makes sense, you can go a step deeper and define each method. For example, bingoFound might look like:
public boolean bingoFound(int[][] board) {
boolean wasFound = bingoRowFound(board)
|| bingoColFound(board)
|| bingoDiagonalFound(board);
return wasFound;
}
Again, I've defined everything in (mostly) pseudo-code. If this looks ok, you can move a step deeper. Let's define the bingoRowFound method.
public boolean bingoRowFound(int[][] board) {
for (int row = 0; row < NUM_ROWS; row++) {
boolean rowIsABingo = true;
for (int col = 0; col < NUM_COLS; col++) {
// We have to check that everything up until this point has
// been marked off. I am using -1 to indicate that a spot has
// been marked.
rowIsABingo = rowIsABingo && board[row][col] == -1;
}
if (rowIsABingo) { return rowIsABingo; }
}
return false; // If we didn't find a bingo, return false.
}
Some of the methods (like drawNumber) will be really easy to implement. Others, like looking for a diagonal bingo might be a bit more difficult.
Feb 12 2014 Update:
Retracted code, since this was a college course assignment, and I want to prevent people just copying the code. I almost got in trouble for being accused of sharing code (which is a nono in assignments) when another student lifted my code from my Github repo and sent it in as their own.
There were two classes, one main class and a class to hold my methods and constructors.
BINGOFINAL.java was my main class.
Bingo_Card.java held my constructor and methods.
If you want to run this, make sure you create a new project called BINGOFINAL, and put Bingo_Card.java into that same */src/ extension.