package com.shan;import java.util.Scanner;public class YFTriangle {public static void main(String[] args) {printYFTriangle();}/*** 1 要理解下面的实现，首先要明白int数组中元素默认值为 0* 2 然后每一次迭代打印新的一行的元素的时候：* 新的特定位置的元素 = 该位置原来的元素 + 该位置的前一个位置的值*/public static void printYFTriangle(){System.out.println("how many lines you want:");Scanner in = new Scanner(System.in);int lines = in.nextInt();int[] a = new int[lines + 1];int previous = 1;for (int i = 1; i <= lines; i ++){for (int j = 1; j <= i; j++){int current = a[j];a[j] = previous + current;previous = current;System.out.print(a[j] + " ");}System.out.println();}}}