杨辉三角规律：

1. 第一行有1个元素，第n行有n个元素；//列数不确定的二维数组
2. 每一行的每一个元素和最后一个元素都是1；
3. 从第三行开始，对于非第一个元素和最后一个元素的元素的值，
   arr[i][j] = arr[i-1][j] + arr[i-1][j-1]

//2024.07.03

public class YangHui {

	public static void main(String[] args) {

		int[][] yangHui = new int[10][];

		for (int i = 0; i < yangHui.length; i++) {
			yangHui[i] = new int[i + 1];

			for (int j = 0; j < yangHui[i].length; j++) {
				if (j == 0 || j == yangHui[i].length - 1) {
					yangHui[i][j] = 1;
				}else{
					yangHui[i][j] = yangHui[i-1][j] + yangHui[i-1][j-1]; 
				}
				
			}
		}

		for (int i = 0; i < yangHui.length; i++) {
			for (int j = 0; j < yangHui[i].length; j++) {
				System.out.print(yangHui[i][j] + "\t");//遍历输出
				
			}
			System.out.println();
		}
	}
}