杨辉三角（输出到n行）

 1 import java.util.*;
 2 
 3 public class Main {
 4     public static void main(String[] args) {
 5         Scanner scanner = new Scanner(System.in);
 6         int n = scanner.nextInt();
 7         int[][] arr = new int[n][n];//将每一行看成一个数组，该数组的长度就是当前行数
 8         for (int i = 0; i < n; i++) {//行
 9             for (int j = 0; j <= i; j++) {//列
10                 if (j == 0 || j == i) {
11                     arr[i][j]=1;
12                     System.out.print(arr[j][j]+"\t");
13                 }else {
14                     arr[i][j] = arr[i-1][j-1]+arr[i-1][j];
15                     System.out.print(arr[i][j]+"\t");
16                 }
17             }
18             System.out.println();
19         }
20     }
21 }