JAVA实现杨辉三角形

public class TestDemo01 {
    public static void main(String[] args) {
        //打印杨辉三角形

        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入需要打印的行数");
        int n = scanner.nextInt();

        int[][] arr = getTri(n);
        printTri(arr);

        scanner.close();
    }

    private static int[][] getTri(int n) {
        int[][] arr = new int[n][n];

        for (int i = 0; i < n; i++){
            arr[i][0] = arr[i][i] = 1;
        }
        for (int i = 2; i < arr.length; i++){
            for (int j = 1; j < i; j++){
                arr[i][j] = arr[i-1][j-1] + arr[i-1][j];
            }
        }
        return arr;
    }

    public static void printTri(int[][] arr){
        for (int i = 0; i < arr.length; i++){
            for (int j = 0; j <= arr.length-1-i; j++){
                System.out.print(" ");
            }
            for (int j = 0; j <= i; j++){
                System.out.print(" ");
                System.out.print(arr[i][j]);
            }
            System.out.println();
        }
    }

}