顺时针打印二维数组（螺旋输出数组）

题目：给定一个数组，将该数组从第一个元素开始顺时针打印出来。

分析：先考虑打印周围一圈的问题，然后可以使用递归求解，直到最后全都打印完为止。也就是先打印最外围的数，然后对于元二维数组中间的数组作为一个新的数组，重新打印该新数组的外围的数，直到最后全部打印完为止。 代码如下：

package problem2;

/**
 * @author Hutongling
 */
public class 顺时针打印二维数组 {
    static void print2DArray(int data[][]) {
        if (data[0].length == 1) {
            for (int i = 0; i < data.length; i++)
                System.out.print(data[i][0] + " ");
            return;
        } else if (data.length == 1 && data[0].length != 1) {
            for (int i = 0; i < data[0].length; i++) 
                System.out.print(data[0][i] + " ");
            return;
        } else if (data.length > 1) {
            int row = data.length;
            int column = data[0].length;
            int i = 0;
            for (i = 0; i < column; i++)
                System.out.print(data[0][i] + " ");
            for (i = 1; i < row; i++)
                System.out.print(data[i][column - 1] + " ");
            for (i = column - 2; i >= 0; i--)
                System.out.print(data[row - 1][i] + " ");
            for (i = row - 2; i >= 1; i--)
                System.out.print(data[i][0] + " ");
            if (row - 2 > 0 && column - 2 > 0) {
                int subData[][] = new int[row - 2][column - 2];
                for (i = 1; i < row - 1; i++)
                    for (int j = 1; j < column - 1; j++)
                        subData[i - 1][j - 1] = data[i][j];
                data = null;
                print2DArray(subData);
            }
        }

    }

    public static void main(String[] args) {
        int data0[][] = {
         
  {
         
  1, 2, 3, 4, 5, 6 }};
        int data[][] = { { 1, 2, 3, 4, 5, 6 }, { 2, 3, 4, 5, 6, 7 }, { 3, 4, 5, 6, 7, 8 }, { 4, 5, 6, 7, 8, 9 } };
        int data1[][] = { { 1, 2, 3, 4 }, { 5, 6, 7, 8 }, { 9, 10, 11, 12 }, { 13, 14, 15, 16 } };
        int data2[][] = { { 1, 2, 3, 4, 5 }, { 2, 3, 4, 5, 6 }, { 3, 4, 5, 6, 7 }, { 4, 5, 6, 7, 8 }, { 5, 6, 7, 8, 9 } };
        int data3[][]={
         
  {
         
  1},{
         
  2},{
         
  3},{
         
  4}};
        print2DArray(data0);
        System.out.println();
        print2DArray(data);
        System.out.println();
        print2DArray(data1);
        System.out.println();
        print2DArray(data2);
        System.out.println();
        print2DArray(data3);
    }

}

结果如下： 1 2 3 4 5 6 1 2 3 4 5 6 7 8 9 8 7 6 5 4 3 2 3 4 5 6 7 6 5 4 1 2 3 4 8 12 16 15 14 13 9 5 6 7 11 10 1 2 3 4 5 6 7 8 9 8 7 6 5 4 3 2 3 4 5 6 7 6 5 4 5 1 2 3 4