「Java学习打卡」18、杨辉三角形

题目一：打印出杨辉三角形。

import java.util.Scanner;

public class Test {
    public static void main(String args[]) {
        System.out.print("请输入打印行数：");
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        int[][] a = new int[n][n];
        System.out.println();
        for (int i = 0; i < n; i++) {
            a[i][0] = 1;
            a[i][i] = 1;
        }
        for (int i = 2; i < n; i++)
            for (int j = 1; j < i; j++)
                a[i][j] = a[i - 1][j - 1] + a[i - 1][j];
        for (int i = 0; i < n; i++) {
            for (int row = 0; row < (n - i) / 2; row++) {
                System.out.print("\t\t");
            }
            if (i % 2 == 0 || n % 2 == 0) {
                System.out.print("\t");
            }
            if (i % 2 != 0 || n % 2 != 0) {
                System.out.print("\t");
            }
            for (int j = 0; j <= i; j++)
                System.out.print(a[i][j] + "\t\t");
            System.out.println();
        }
    }
}