在二维数组中填入主对角线(Filling in the main diagonals in a 2D array)

 我试图编写一个代码来填充NxN矩阵中的2个主要对角线，例如：如果N = 5（通过命令行输入），我们将有一个填充0的5x5矩阵，对角线将有2s填入，如： 
 
2 0 0 0 2
0 2 0 2 0
0 0 2 0 0
0 2 0 2 0
2 0 0 0 2
 
 我写了一个全零表的代码，但是我不知道如何填写对角线。 看看5x5的情况，我将不得不填写以下指数的矩阵： 
 
#1 (0,0)  (0,n-1) 
#2 (1,1) (1,n-2)
#3 (2,2) (2,n-3) 
#4 (3,1) (3, n-2)
#5 (4,0) (4,n-1)
 
 但是，由于N可以是任意数字，我假设首先我必须找到中间行，之后我必须以相反的顺序递减索引。 
 
 我只学了2周的Java，而这个很难。 我的代码为零填充表是这样的： 
 
public static void main (String[] args){
        int n = Integer.parseInt(args[0]);
        System.out.println(n);
        int[][] table = new int[n][]; 
         for (int i = 0; i < n; i++) { 
         table[i] = new int[i + 1]; 
         for (int j = 0; j <= i; j++) { 
         table[i][j] = (0); 


            }
        } System.out.print(Arrays.deepToString(table));
    }
 
 显然，这与我所需要达到的目标相去甚远，我不确定它是否完全正确。 我真的很感谢一些帮助。 

I am trying to write a code that fills in the 2 main diagonals in an NxN matrix, for example: if N=5 (which is entered through command line), we would have a 5x5 matrix filled with zeros and the diagonals would have 2s filled in, like:
 
2 0 0 0 2
0 2 0 2 0
0 0 2 0 0
0 2 0 2 0
2 0 0 0 2
 
I wrote a code for an all-zero table, but i can't figure our how to fill in the diagonals. Looking at the case of 5x5 i would have to fill in the matrix at the following indices:
 
#1 (0,0)  (0,n-1) 
#2 (1,1) (1,n-2)
#3 (2,2) (2,n-3) 
#4 (3,1) (3, n-2)
#5 (4,0) (4,n-1)
 
However, since N can be any number, i assume that first i have to find the middle row, after which i have to decrement the indices in the reverse order.
 
I am learning Java for 2 weeks only and this one is pretty hard. My code for a zero-filled table is this:
 
public static void main (String[] args){
        int n = Integer.parseInt(args[0]);
        System.out.println(n);
        int[][] table = new int[n][]; 
         for (int i = 0; i < n; i++) { 
         table[i] = new int[i + 1]; 
         for (int j = 0; j <= i; j++) { 
         table[i][j] = (0); 


            }
        } System.out.print(Arrays.deepToString(table));
    }
 
Obviously, this is very far from what i need to achieve, and i am not sure if it's entirely right. I would really appreciate some help.

原文：https://stackoverflow.com/questions/22204140