一个算法题！

Question

描述如下：
n=1时：
输出 0 1 0
    4 5 2
    0 3 0
n=2时：
输出：
    0  1 2  0
   8  9 10 3
   7 12 11 4
   0  6  5  0
 依次类推，螺旋输出。

Answer 1

public class HelixTest
{
private static int[][] helixNum(int n) {
int len=n+2;
int[][] array=new int[len][len];
        int count = len*len-4;
        int direct = 0;
        int round = 1;
        for(int index = 1, x = 0, y = 0; index <= count; index++) {
if(((x==0)&&(y==0||y==len-1))||(x==len-1)&&(y==0||y==len-1)){
array[x][y]=0;
index--;
}
else{
array[x][y] = index;
}
            switch(direct) {
                case 0: 
                    if(y < len - round)
                        y++;
                    else {
                        direct = 1;
                        x++;
                    }
                    break;
                case 1:
                    if(x < len - round)
                        x++;
                    else {
                        direct = 2;
                        y--;
                    }
                    break;
                case 2:
                    if(y >= round)
                        y--;
                    else {
                        direct = 3;
                        x--;
                    }
                    break;
                case 3:
                    if(x > round)
                        x--;
                    else {
                        direct = 0;
                        round++;
                        y++;
                    }
                    break;                        
            }
        }
return array;
    }
public static void main(String[] args){
int[][] intArr=helixNum(2);
for(int i=0;i<intArr.length;i++){
for(int j=0;j<intArr[i].length;j++){
System.out.print(intArr[i][j]+" ");
}
System.out.println();
} }
}