打印杨辉三角形详解编程语言

 1 package com.li.FiftyAlgorthm; 
 2  
 3 /** 
 4  * 题目：打印出杨辉三角形（要求打印出10行如下图） 
 5             1 
 6            1 1 
 7           1 2 1 
 8          1 3 3 1 
 9         1 4 6 4 1 
10        1 5 10 10 5 1 
11  *  a[i][j]=a[i-1][j]+a[i-1][j-1] 就是这个程序的核心 
12  *  
13  * @author yejin 
14  */ 
15 public class YangTriangle { 
16     public static void main(String[] args) { 
17         int[][] a = new int[10][10]; 
18         for (int i = 0; i < 10; i++) { 
19             a[i][i] = 1; 
20             a[i][0] = 1; 
21         } 
22         for (int i = 2; i < 10; i++) { 
23             for (int j = 1; j < i; j++) { 
24                 a[i][j] = a[i - 1][j - 1] + a[i - 1][j]; 
25             } 
26         } 
27  
28         for (int i = 0; i < 10; i++) { 
29             for (int k = 0; k < 2 * (10 - i) - 1; k++) { 
30                 System.out.print(" "); 
31             } 
32             for (int j = 0; j <= i; j++) { 
33                 System.out.print(a[i][j] + "   "); 
34             } 
35             System.out.println(); 
36         } 
37     } 
38 }