C#29. 顺时针打印矩阵

输入一个矩阵，按照从外向里以顺时针的顺序依次打印出每一个数字。

示例 1：

输入：matrix = [[1,2,3],[4,5,6],[7,8,9]]
输出：[1,2,3,6,9,8,7,4,5]
示例 2：

输入：matrix = [[1,2,3,4],[5,6,7,8],[9,10,11,12]]
输出：[1,2,3,4,8,12,11,10,9,5,6,7]

限制：

0 <= matrix.length <= 100
0 <= matrix[i].length <= 100
采用边界发

public class Solution {
    public int[] SpiralOrder(int[][] matrix) {
        if (matrix.Length == 0 || matrix[0].Length == 0)
            return new int[0];

        int rowLen = matrix.Length, colLen = matrix[0].Length;
        int[] res = new int[rowLen * colLen];
        int i = 0, j = 0, cur = 0, circle = 0;
        while (cur != res.Length) {
            while (j < colLen - circle && cur != res.Length)
                res[cur++] = matrix[i][j++];
            --j;
            ++i;
            while (i < rowLen - circle && cur != res.Length)
                res[cur++] = matrix[i++][j];
            --i;
            --j;
            while (j >= 0 + circle && cur != res.Length)
                res[cur++] = matrix[i][j--];
            ++j;
            --i;
            while (i >= 1 + circle && cur != res.Length)
                res[cur++] = matrix[i--][j];
            ++i;
            ++j;
            ++circle;
        }
        return res;
    }
}