一道打印M的面试题

package cn.itcast.dom4j;public class Demo1 {/*   3       7 2   4   6   8    1      5       9    平面图形题（二维数组）    */public static void main(String[] args){int num = 13;int height = num/4+1;int width = num;int arr[][] = new int[height][width];int x = height-1;int y = 0;boolean order = false;for(int i = 1;i<=num;i++){arr[x][y] = i;y++;if(!order){x--;}if(order){x++;}if(x<0){order = true;x = x+2;}if(x>height-1){order = false;x = x-2;}}for(int i = 0;i<arr.length;i++){for(int j = 0;j<arr[i].length;j++){if(arr[i][j]==0){System.out.print(" ");}elseSystem.out.print(arr[i][j]);}}System.out.println();}}