/**
     * 1 3 6 10
     * 2 5 9
     * 4 8
     * 7
     * <p>
     * <p>
     * 0-0 0-1 0-2 0-3
     * 1-0 1-1 1-2
     * 2-0 2-1
     * 3-0
     */

题目要求是输出 如上 的数字矩阵,于是找到下标的规律,解题如下

public static void main(String[] args) throws Exception {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
Integer num = Integer.valueOf(br.readLine());
int jia = 1;
// 创建二级数组
int er[][] = new int[num][];
for (int i = 0; i < num; i++) {
// 每级数组 存放多少数
er[i] = new int[num - i];
for (int j = 0; j < i + 1; j++) {
er[i-j][j] = jia;
jia++;
}
}
for (int i = 0; i < er.length; i++) {
for (int j = 0; j < er[i].length; j++) {
System.out.print(er[i][j] + " ");
}
System.out.println();
}
}