Output Yang Hui triangle with two-dimensional array

Punch in the first day of study , Use Java Output Yanghui triangle can customize the number of output lines

Yanghui triangle example ：

1 
1 1 
1 2 1 
1 3 3 1 
1 4 6 4 1 
1 5 10 10 5 1 
1 6 15 20 15 6 1

It can be seen that , The rule is that the value of the first element and the last element in each line is 1, Other element values are the sum of the value above the element and the previous value above .

Code implementation ：

package array;
import java.util.Scanner;
public class TwoArray02 {
public static void main(String[] args){
	Scanner myScanner=new Scanner(System.in);
	System.out.println(" Please output the number of lines to be printed ：");
	int n=myScanner.nextInt();// Enter the number of lines 
	int[][] arr=new int[n][];// Create a 2D array 
	for(int i=0;i<arr.length;i++){// Traverse the number of one-dimensional arrays in two-dimensional arrays 
		arr[i]=new int[i+1];// Open up space for one-dimensional arrays 
		for(int j=0;j<i+1;j++){// Traverse the element values of each one-dimensional array 
			if(j==0||j==arr[i].length-1){// The first and last elements of each line are 1
				arr[i][j]=1;
			}
			else{// Other element values are the sum of the value above the element and the previous value above 
				arr[i][j]=arr[i-1][j]+arr[i-1][j-1];
			}
			System.out.print(arr[i][j]+" ");
		}
		System.out.println();
	}
	
}
}