java打印杨辉三角

import java.util.Scanner;/*** *   杨辉三角 * @author 小健 * */public class ArrayTest05_杨辉三角 {/* *     1 *     1  1 *    1  2  1 *     1  3  3  1 *     1  4  6  4  1 */public static void main(String[] args) {Scanner sr = new Scanner(System.in);System.out.println("请输入行数：");int b = sr.nextInt();int[][] a = new int[b][];for(int i=0;i<a.length;i++){a[i] = new int[i+1];for(int j=0;j<a[i].length;j++){if(j==0||i==0||j==i){a[i][j]=1;}else{a[i][j]=a[i-1][j-1]+a[i-1][j];}System.out.print(a[i][j]+"  ");}System.out.println();}}}