Java 2 D配列印刷楊輝三角形

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("        ");
        int n = sc.nextInt();

        int[][] arr = new int[n][n];
        for (int i = 0; i < arr.length; i++) {
            for (int j = 0; j < arr[i].length; j++) {
                arr[i][0] = 1;
                arr[i][i] = 1;

            }
        }
        for (int i = 2; i < arr.length; i++) {
            for (int j = 1; j < arr[i].length - 1; j++) {
                arr[i][j] = arr[i - 1][j - 1] + arr[i - 1][j];
            }

        }

        for (int i = 0; i < arr.length; i++) {
            for (int j = 0; j <= i; j++) {
                System.out.print(arr[i][j] + "\t");
            }
            System.out.println();
        }
    }
/*
  ：          1；
                          。
         ：
1   
1   1   
1   2   1   
1   3   3   1   
1   4   6   4   1   
1   5   10  10  5   1   
1   6   15  20  15  6   1   
1   7   21  35  35  21  7   1   
1   8   28  56  70  56  28  8   1   
1   9   36  84  126 126 84  36  9   1   

*/