JAVA如何生成1到24之间的整数，但每个整数都需要一对

Question

I'm making the memory game concentration. In this I have a specified obligation to generate random pairs of numbers. These are to be assigned to a cell at its creation on a game board. My problem lies not in how to generate a random number as I am able to do this with --

type = generator.nextInt(NUMBER_OF_ROWS*NUMBER_OF_COLUMNS);

However I must make sure that when I am populating my game board with Cell objects

board[row][column] = new Cell(this,type, row, column);

I have 2 cells of the same type, in order for the game to function. Basically I need 12 pairs of numbers that have been randomly generated.

Thanks

Varun

Answer 1

Invert the problem. Rather than think of generating 24 random numbers, what you really want is to distribute the numbers 1-12 randomly into a 24-cell array, with each number going into TWO randomly selected cells in the array. The simplest way to do this would be be to create a List<Cell> , populate it with 24 cells (two containing value 1, two containing value 2, etc), and then use Collections.shuffle(List<?>...)

Answer 2

The question is not clear. But I think you want to have two cells of same type ie you have 24 cells and you want to make 12 pairs of them. If you want the cells to be random you can generate two random rows number and two random column number and pair them. You have to look that the pair is not repeated.

EDIT: No function can generate pair of numbers. What you can do is number the cells in 2-D array , like suppose the row count is 3 and columns is 2 then number it like 0,1,2,3,4,5. Now start generating random numbers and set the upper limit to 5. Suppose the first no. generated is 2 and second one is 5 then you can call it a pair. Then again generate the numbers. Next pair can 1 and 0 and so on.

Answer 3

It looks like you are not familiar with 2 Dimensional arrays or my understanding of the question is wrong. I think the game requires the player to remember a pair of cells. Totally there are 12 pairs so have a 2D array with one index varying from 0 to 11 which denotes pair number and another index which distinguishes the two cell numbers in a pair.

You need to store in an integer array called pairtype[12][2] two numbers which are paired. Say suppose cell no 1 is paired with 15 then there will be one value {1,15} in the array pairtype. So you can store 12 pairs of two integers in the array pairtype.

What mistake you are doing is using type which can range from 0 to 23 to assign to a cell type. Instead use the first index(index1) of pairtype[index1][index2] as cell type which will then vary from 0 to 11.

You also need to take care not to generate pairs like {1,15} and {1,12} in the array pairtype.