小练习

1.杨辉三角

public class 杨辉三角 {
    public static void main(String[] args) {
        //1.声明并初始化二维数组
        int[][] yangHui = new int[10][];
        
        //2.给数组的元素赋值
        for(int i = 0;i < yangHui.length;i++) {
            yangHui[i] = new int[i + 1];
            yangHui[i][0] = yangHui[i][i] = 1;
            for(int j = 1;j < yangHui[i].length - 1;j++) {
                yangHui[i][j] = yangHui[i-1][j-1] + yangHui[i-1][j];
            }
        }
        
        //3.遍历二维数组
        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();
        }
    }
}