public class Arryays{

    public static void main(String args[]) {
        int i, j;
        char a[][] = new char[5][];
        a[0] = new char[1];
        a[1] = new char[3];
        a[2] = new char[5];
        a[3] = new char[7];
        a[4] = new char[9];
        a[0][0] = 'a';
        for (i = 0; i < 3; i++)
            a[1][i] = 'b';
        for (i = 0; i < 5; i++)
            a[2][i] = 'c';
        for (i = 0; i < 7; i++)
            a[3][i] = 'd';
        for (i = 0; i < 9; i++)
            a[4][i] = 'e';
        for (i = 0; i < 5; i++) { // 外层循环5次，打印5行字母
            for (j = 15 - i; j > 0; j--)//表示每行打印字母前打印的空格数，第一行15个，依次递减
                System.out.print(" ");
            for (j = 0; j <= 2 * i; j++) {//表示每行打印同一字母的个数，和行数相关的规律
                System.out.print(a[i][j] + "");
            }
            System.out.println();
        }
    }
}