使用Java中的数组创建滑动数字拼图板

Question

So I'm kind of new to Java and decided to create a sliding number puzzle of some sort. Here's what I have :

int[] puz = {1,2,3,
             4,5,6,
             7,8,9}
for(int i=0; i<puz.length; i++){
    System.out.println(puz[i]);
}

The 1 is supposed to be the blank spot but I'll figure that out later. My problem is that the code prints:

1
2
3
4
5
6
7
8
9

when I want it to print:

1 2 3
4 5 6
7 8 9

I've also tried doing a nested loop that I'm too embarrassed to show on here due to how hideous it was. Would I try using a 2d array instead?

Answer 1

I guess you could try...

int puz = {1,2,3,4,5,6,7,8,9};
int n = Math.ceil(Math.sqrt(puz.length));
for (int i = 0; i < puz.length; i++) {
    System.out.print(puz[i] + ((i + 1) % n == 0 ? "\r\n" : " ");
}

Answer 2

Try creating a variable counter and increment it every time you iterate through the loop. Using a modulus operator, divide it by 3 and when remainder is 0, create a new line.

int puz = {1,2,3,4,5,6,7,8,9};

int counter = 1;
for(int i=0; i<puz.length; i++){
    System.out.print(puz[i]);
    if (counter % 3 == 0){
        System.out.println("");
    }
    counter++;
}

Answer 3

The trick here is to use the modulus operator. This operator divides one number by another, and returns the remainder. In java (and everywhere else as far as I know), % is the modulus operator. If you want every third number to have a line break after it, simply divide by three using modulus division, like so:

int[] puz = {1,2,3,4,5,6,7,8,9};
    //For what it's worth, you don't have this semicolon in your question, so I added it in.
for(int i=0; i<puz.length; i++){
    System.out.print(puz[i] + " ");
    if(i % 3 == 2){//It's equal to 2 because you start at 0 and not 1.
        System.out.println("");
    }
}

This code, when executed, prints the following, which is what you wanted:

1 2 3 
4 5 6 
7 8 9