今日份学习打印10行杨辉三角

杨辉三角规律

package pg1;
/*
 * 输出10行杨辉三角 
*/

public class YangHuiTest {
    
    
	public static void main(String[] args) {
    
    
		// 1.声明并初始化二维数组
		int[][] YangHui = new int[10][];

		// 给二维数组的元素赋值
		for (int i = 0; i < YangHui.length; i++) {
    
    
			// 确定每行元素的个数
			YangHui[i] = new int[i + 1];
			// 确定每行首末元素为1
			YangHui[i][0] = 1;
			YangHui[i][i] = 1;

			// 对非首末元素赋值
			if (i > 1) {
    
    
				for (int j = 1; j < YangHui[i].length - 1; j++) {
    
    
					YangHui[i][j] = YangHui[i - 1][j] + YangHui[i - 1][j - 1];
				}
			}
		}

		// 输出二维数组的元素
		for (int i = 0; i < YangHui.length; i++) {
    
    
			for (int j = 0; j < YangHui[i].length; j++) {
    
    
				System.out.print(YangHui[i][j] + "  ");
			}
			System.out.println();
		}
	}
}